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Show 1900.] NEW SPECIES OF EARTHWORM. 655 have been examined microscopically; our knowledge of the more minute structure of the genus is indeed limited to that of the smaller forms. I have investigated the structure of the body-wall in the present species, which shows certain features worthy of note. The first point to which I direct attention is the vascularity of the epidermis. This structual peculiarity occurs, but is not common, among earthworms. I was myself the first to announce that certain Oligochaeta resemble the Leeches (in which group the fact had been previously ascertained by Lankester) in having a vascular epidermis.1 This character, however, has not been found in many earthworms. It seems to m e therefore to be worth recording the fact that the Benhamia which forms the subject of the present communication has a vascular epidermis. It appeared to m e moreover to be more abundantly vascular than I have observed to be the case elsewhere. The capillaries are very readily seen owing to their being injected with their own blood; they penetrate the actual epidermis as loops which reach perhaps halfway through the thickness of the epidermic layer. I could find no trace of their opening on to the exterior, which has been asserted by the Messrs. Sarasin in the case of Perichceta. It is also to be noted that in the anterior region of the body, at any rate in the neighbourhood of the spermathecae, intra-epi-dermic capillaries are so rare as to be practically absent. I only saw one or two loops in a large number of sections. They can be of but little functional importance in this part of the body; but they are clearly of great functional importance towards the hinder end of the body. As a matter of fact these capillaries do not apparently penetrate the epidermis at the very end of the body ; but this may conceivably be due to fresh growth in this region. That the epidermis should be especially vascular posteriorly is interesting when we reflect that it is in this situation that gills are chiefly developed in branchiate Oligochaeta. A second point of interest concerning the body-wall of this species is that the longitudinal muscles have the bipinnate arrangement, first described by Claparede in Lumbricus, but not by any means universal among earthworms. Internal Structure. The accompanying drawing (fig. 2, p. 656) illustrates a general view of the internal viscera, and expresses at the same time some of the specific peculiarities of the species. The anterior portion of the two gizzards (which completely hide the underlying spermathecae) is to be noticed. The position of the calciferous glands (ca), the last pair of which are situated in the xvith segment, is important; and also the fact that the large intestine may be said to commence in the xxist segment, as it does not attain to its greatest 1 " On the Anatomy and Histology of Pleurochceta moseleyi," Trans. Roy. Soc. Edinb. 1880, and " On the Structure of the Body-wall in certain Earthworms," Proc. Roy. Phys. Soc. Edinb. 1881. 43* |