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| Registros recuperados: 44 | |
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| Hammen, L. van der. |
| A comparative study is made of four chelicerate classes: Apatellata (Solifugae and Pseudoscorpionida), Arachnida s. str. (both groups of Uropygi, i.e. Holopeltida and Schizomida, Amblypygi and Araneida), Scorpionida and Xiphosura. Methods, principles and terminology, adopted in this paper, correspond with those of parts I -111 of the present series of comparative studies in Chelicerata. Special attention is paid to segmentation of the body, respiratory organs, orifices of coxal glands, mouthparts, and appendages. The evolution of these structures is studied, and the relationships of the chelicerate classes and subclasses are reinvestigated and discussed. |
| Tipo: Article / Letter to the editor |
Palavras-chave: Amblypygi; Apatellata; Arachnida; Araneida; Chelicerata; Evolution; Holopeltida; Morphology; Pseudoscorpionida; Schizomida; Scorpionida; Solifugae; Uropygi; Xiphosura.; 42.74. |
| Ano: 1986 |
URL: http://www.repository.naturalis.nl/record/317847 |
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| Hammen, L. van der. |
| In the present study of the Anactinotrichid order Holothyrida, five species are dealt with: Australothyrus ocellatus nov. gen., nov. spec. (family Allothyridae) from Queensland, Australia; Hammenius (Leiothyrus) holthuisi nov. subgen., nov. spec. and Hammenius (Thonius) montanus nov. spec. (family Holothyridae), both from New Guinea; and Holothyrus coccinella Gervais and Holothyrus legendrei nov. spec. (family Holothyridae), both from Mauritius. The paper includes detailed studies of the morphology, a study of the postembryonic development, a reclassification of the species of the family Holothyridae, and notes on the relationships of the order Holothyrida. |
| Tipo: Article / Letter to the editor |
Palavras-chave: 42.74. |
| Ano: 1983 |
URL: http://www.repository.naturalis.nl/record/317620 |
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| Hammen, L. van der. |
| Het Vogeljaar door Jac. P. Thijsse, waarvan in 1969 de zesde druk verscheen, is door zijn in opeenvolgende drukken herhaaldelijk wisselend uiterlijk, een interessant historisch object geworden. De tekst evolueerde langzaam, doordat bij iedere nieuwe druk nieuwe gegevens werden toegevoegd en kleine correcties werden aangebracht. Op het gebied van illustraties, formaat, typografie en bandversiering hadden echter bijna steeds (behalve bij de derde druk die veel lijkt op de tweede) ingrijpende veranderingen plaats. In grote lijnen kan men zeggen dat de eerste drie drukken nauw verbonden zijn met de kring van medewerkers aan het tijdschrift De Levende Natuur, de volgende drie drukken met die van medewerkers aan De Wandelaar. Door vergelijking van de drukken kan... |
| Tipo: Article / Letter to the editor |
Palavras-chave: 42.01. |
| Ano: 1972 |
URL: http://www.repository.naturalis.nl/record/317235 |
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| Hammen, L. van der. |
| INTRODUCTION The study of the Oribatei (moss mites or beetle mites) of the Netherlands was started by Oudemans, who in 1896 published his "List of Dutch Acari, First Part, Oribatei", that was followed in 1900 and 1902 by a first and by a second part of a "New List". After that time Oudemans repeatedly published papers in which Oribatei of the Netherlands were dealt with, although in his later years he paid less attention to this group of Acari. Only a part of the moss mites that Oudemans collected were mentioned by him; a preliminary catalogue of his collection, containing some hitherto unpublished faunistical data on Oribatei, appeared after his death (Buitendijk, 1945). Willmann (1930) published a note on interesting Oribatei in the Oudemans Collection,... |
| Tipo: Article / Letter to the editor |
Palavras-chave: 42.74. |
| Ano: 1952 |
URL: http://www.repository.naturalis.nl/record/317841 |
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| Hammen, L. van der. |
| In the first part of the present series (Van der Hammen, 1966), I estimated the extent of my studies on Opilioacarida at two papers, each paper dealing with a representative of one genus. Since the publication of this first part, however, new material has been placed at my disposal, enabling me to start a revision (to be published in several parts) of nearly all species of the group described up to now. Such a revision is interesting because of two reasons. In the first place Opilioacarida are characterized by a very homogeneous habitus which is in remarkable contrast with the considerable variability of many other characters, in such a way demonstrating the further evolution of a type probably fixed at an early date. In the second place, a thorough... |
| Tipo: Article / Letter to the editor |
Palavras-chave: 42.74. |
| Ano: 1968 |
URL: http://www.repository.naturalis.nl/record/319151 |
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| Boelé, F.E.; Hammen, L. van der. |
| In the present paper an analysis is made of the variation in the number of ungues in the claws of Ameronothrus schneideri (Oudemans), an Oribatid mite. This variation is attributable to the regression of the two lateral ungues which are completely suppressed in the course of evolution (they are either present or absent). The laws of this numerical evolution (it is a so-called vertitional evolution) appear to be statistical, and do not determine individual events precisely (as the laws of the particles in quantum mechanics). In a population, each of the claws has a probability of manifestation. The variation of this probability of manifestation shows a very interesting geographical pattern which is as yet difficult to explain. Various correlations of the... |
| Tipo: Article / Letter to the editor |
Palavras-chave: 42.74. |
| Ano: 1982 |
URL: http://www.repository.naturalis.nl/record/318543 |
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| Hammen, L. van der. |
| In the first three parts of the present series (Van der Hammen, 1966, 1968, 1969) I have dealt with four species of Opilioacarida, viz., Opilioacarus texanus (Chamberlin & Mulaik), Paracarus hexophthalmus (Redikorzev), Opilioacarus platensis (Silvestri), and Adanacarus arabicus (With). The detailed redescription of Opilioacarus texanus (the first part of the series) constituted the morphological base for the subsequent studies. In the meantime, I completed a glossary of opilioacarid terminology (Van der Hammen, 1976), in which not only terminology, but also notations, measurement, description and orientation of figures are standardized. Consequently the continuation of my series of studies on Opilioacarida is now based on the above-mentioned glossary.... |
| Tipo: Article / Letter to the editor |
Palavras-chave: 42.74. |
| Ano: 1977 |
URL: http://www.repository.naturalis.nl/record/319056 |
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| Hammen, L. van der. |
| In the course of my investigations in the field of comparative acarid morphology (Van der Hammen, 1961, 1963, 1964, 1964a, 1965, 1966, 1968, 1968a, 1968b, 1968c, 1969, 1969a, 1970, 1970a, 1970b), I have paid attention to various groups of mites, viz., all orders of Anactinotrichida, except Ixodida (apart from a small paper on the palp) ; and all orders of Actinotrichida, except Tarsonemida and Acaridida. One of the most important gaps is now constituted by the Tarsonemida, of which the systematic position has been controversial, although recent authors generally classified the group with the Trombidiformes or Prostigmata. Published data on the morphology, notwithstanding the fact that very important studies have recently appeared (e.g. Beer, 1954; Cross,... |
| Tipo: Article / Letter to the editor |
Palavras-chave: 42.74. |
| Ano: 1970 |
URL: http://www.repository.naturalis.nl/record/317759 |
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| Hammen, L. van der. |
| Morphology has developed rather differently in each of the large groups of mites. Our knowledge on the subject is nowadays at unequal levels, so that terminology, method, and way of interpretation are difficult to compare. This has resulted at present in a more or less unsurveyable condition of acarology as a whole. It is evident that a comparative acarid morphology is only possible when representatives of each group are studied, described, and figured according to the same method. In order to build up a survey of the mites based on these principles, I recently started a study of the Anactinotrichida according to methods used in oribatology. In 1961 I published an extensive description of a species of Holothyrus, with notes on characters generally... |
| Tipo: Article / Letter to the editor |
Palavras-chave: 42.74. |
| Ano: 1964 |
URL: http://www.repository.naturalis.nl/record/317689 |
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| Hammen, L. van der. |
| The present paper constitutes an introduction to taxonomic methodology. After an analysis of taxonomic practice, and a brief survey of kinds of attributes, the paper deals with observation, description, comparison, arrangement and classification, hypothesis construction, deduction, model, experiment, abstraction, and synthesis. The methodological aspects of the species-concept and of biological classification are dealt with in two final sections. |
| Tipo: Article / Letter to the editor |
Palavras-chave: Abstraction; Classification; Comparison; Deduction; Description; Experiment; Hypothesis; Methodology; Model; Observation; Species-concept; Synthesis; Systematics; Taxonomy; 42.03; 42.70. |
| Ano: 1986 |
URL: http://www.repository.naturalis.nl/record/318283 |
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| Hammen, L. van der. |
| The present paper is the first part of a series of two studies dealing with the morphology of the suborder Holothyrina. Some years ago (Van der Hammen, 1961), I published already an extensive description of a species from New Guinea (Holothyrus grandjeani Van der Hammen), in which paper I pointed to a number of important characters generally neglected in the study of Anactinotrichida. Because my material of H. grandjeani contained only one adult specimen, a number of characters (e.g. details to be studied in transverse as well as in longitudinal sections) could, however, not be taken into consideration. As a result of my 1961 study, a reinvestigation of nearly all species of Holothyrus, and especially of the type-species (H. coccinella), became highly... |
| Tipo: Article / Letter to the editor |
Palavras-chave: 42.74. |
| Ano: 1965 |
URL: http://www.repository.naturalis.nl/record/318632 |
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| Hammen, L. van der. |
| A study is made of John Ruskin's work in the field of zoology. It is demonstrated that Ruskin's early interest in zoology was connected with his study of ornament, whilst his later studies are connected with his Oxford teaching and his social work. Ruskin's interest in zoology concerned groups frequently represented in art (particularly birds and snakes). Of these groups he studied, in a fragmentary way, the artistic morphology, the life-habits, the particular position to art and literature, and the mythological signification. Besides that, his natural history teaching was focussed on the protection of animals and respect for nature. |
| Tipo: Article / Letter to the editor |
Palavras-chave: 42.01. |
| Ano: 1983 |
URL: http://www.repository.naturalis.nl/record/318416 |
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| Hammen, L. van der. |
| It is a generally accepted concept nowadays that dichotomy is the most primitive type of ramification in land plants. Recently Lam (1948) briefly reviewed the literature of this subject in the light of the telome theory. He recalled that the dichotomies of fern leaves are to be regarded as homologous to the dichotomies of stems in more primitive plants and enumerated a number of more or less haphazardly collected cases in higher plants, of which the most probable interpretation is that they are traces of such ancient dichotomies, betraying their original relation to a branch system. In his paper, Lam discriminated between such traces in vegetative and in reproductive parts and he arrived at the provisional conclusion that traces of ancient dichotomies in... |
| Tipo: Article / Letter to the editor |
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| Ano: 1947 |
URL: http://www.repository.naturalis.nl/record/524431 |
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| Hammen, L. van der. |
| Progress in classification of Chelicerata has been thwarted especially by two factors, viz., the concept of mites as one monophyletic group, and the opinion that this group consists of species with a highly modified plan of construction and without any trace of true segmentation. The only characters which are generally shared by all groups of mites refer to the presence of a gnathosoma (i.e. the cone-shaped, movable structure comprizing the mouthparts), and the occurrence of a larva with only three pairs of legs (the last-mentioned character is also found in Ricinulei). A comparative morphological study of the gnathosoma (Van der Hammen, 1970b, 1972) has, however, demonstrated that two fundamentally different types can be distinguished, which must be the... |
| Tipo: Article / Letter to the editor |
Palavras-chave: 42.74. |
| Ano: 1977 |
URL: http://www.repository.naturalis.nl/record/319210 |
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| Hammen, L. van der. |
| A study is made of the Arachnid fauna of the subterranean limestone quarries in Southern Limburg, The Netherlands. About a hundred quarries have been investigated, and ten species of Opilionida, three species of Pseudoscorpionida and fifty-six species of Araneida are listed here. Among the species most frequently met with are: Nesticus cellulanus (Clerck), Meta merianae (Scopoli), Lepthyphantes pallidus (O. P.-Cambridge), Tegenaria silvestris L. Koch, Meta menardi (Latreille), Lepthyphantes leprosus (Ohlert), Amaurobius ferox (Walckenaer) and Paranemastoma quadripunctatum (Perty) (species arranged according to decreasing frequency). |
| Tipo: Article / Letter to the editor |
Palavras-chave: 42.74. |
| Ano: 1983 |
URL: http://www.repository.naturalis.nl/record/317194 |
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| Registros recuperados: 44 | |
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