OCR Text |
Show 906 MR. F. E. BEDDARD ON THE [Dec. 4, (12) Amyntas minutus, n. sp. Of this very small species I have examined only a single specimen, which is 48 m m . in length. I counted 103 segments. The setae upon the anterior segments are very large. The clitellum occupies the whole of segments xiv.-xvi. It has setae upon it. The median region of the xvith segment is not invaded by glandular tissue, so that it presents the appearance of a papilla. There is a swollen area of corresponding position and extent upon segment xvii. Apart from these there are a series of paired genital papillce which follow the male pores upon segments xix.-xxi. They are paired upon the first two segments, but the xxist has only the left-baud one. They are much smaller than the male pores and lie nearer to the middle line. The male pores are very large indeed. They are shallow but large depressions borne upon very conspicuous porophores. They are sucker-like in appearance. With regard to the internal structure, I have been able by dissection to note the principal structural features which fix the position of and distinguish the present species. I a m not certain, however, whether the gizzard-septum is present. The gizzard itself is large and typically ' pericbaetous '; the failing or vanished gizzard of some small Earthworms is sometimes put down to small-nessof size and consequent simplification by degeneration; instances like tbe present appear to show that the reduction of the gizzard is rather to be referred to difference of habitat and food. The intestine has no cceca. I could not fix the position of the last heart. There are undoubtedly three pairs of large sperm-sacs, which lie in segments x.-xii. The spermiducal glands are large, loose in texture, and much incised. The duct is rather long ; it runs forward and then back, opening directly on to the exterior, and not by the way of a terminal sac. The gland itself extends through segments xvi.-xxi. The spermatheca, present the unusual character of being massed in considerable numbers in a single segment. There are 6-10 pairs of them, not only in segments vi. & vii. as in A. stelleri, but also in segment viii. behind the last thick septum and alongside of the gizzard. Hab. Aring. The following will be the definition of Amyntas minutus, n. sp. Length 48 m m . ; number of segments 103. Setae on anterior segments larger. Clitellum xiv.-xvi., with setae. Papillae paired on xix.-xxi., smaller and nearer to the middle line than the prominent, widely separate male pores. Caeca absent. Sperm-sacs iu x.-xii. Spermiducal glands xvi.-xxi., with longish duct and no end-sac Spermathecae 6-10 pairs in each of segments vi.-viii. Hab. Malay Peninsula. |