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Show 786 MR. D. J. SCOURFIELD O N T H E [June 15, with earth, so that the samples may probably be considered as fairly typical. Before passing to the detailed notes upon the various groups of animals represented in the mosses, a few words on two of the more general results of the examination may not be out of place. First as regards the relative importance of the different groups from the point of view of their abundance. In this connection it may be remarked that although the micro-plants were not systematically looked for, one could not help being struck with the comparative abundance and variety of the Diatoms, whilst on the other hand the paucity of the Desmids was equally noticeable. The latter were in fact confined to a few individuals of one or two small species of Cosmarlum. Of the animals, the dominant groups were undoubtedly the Bhizopoda and Nematoda, the former being, however, by far tbe most abundant. Next in order of importance came the Botifera, Collembola, Infusoria, Chaetopoda, and Tardigracla. The remaining groups, namely the Gastrotricha, Acarina, Entomo-straca, and Insect larvae, were only represented by a few solitary specimens here and there. The other result to be mentioned, and the one of most general significance, is that, so far as can be judged from the evidence now collected, the micro-fauna of Spitsbergen includes very few peculiar species. With but two or three exceptions, the most certain being, moreover, in a group (Tardigrada) which has been much neglected by naturalists, all the forms seen appear to have been previously found in Europe and North America. "We have here, therefore, still further evidence of the enormous geographical range of many species of the lower forms of animal life, especially of the fresh-water forms, and of the really remarkable variations in external conditions under which they can not only exist but even thrive. BHIZOPODA. Animals belonging to this class formed a very large proportion of the organisms found in the mosses. As will be seen from the detailed list, about twenty-one species in all were noted, and although some of these cannot be referred to named forms, it is almost certain that none of them are new to science. They are practically the same forms as one could find in damp mosses almost anywhere in England, on the Continent, or in North America. Iu fact, with the exception of abnormal specimens, almost every individual Bhizopod from these Spitsbergen mosses could be matched by a figure in Leidy's ' Fresh-water Bhizopods of North America' (Washington, 1879). One point that deserves mention is the large number of specimens seen presenting abnormalities in the shape of the shell. This was especially noticeable with Euglypha cillata, but also occurred in Nebela collaris and other species. It is tempting to refer this back to the influence of the severe climatic conditions under which the animals live in Spitsbergen, but with the exception of two |
