| OCR Text |
Show 198 MR. F. E. BEDDARD ON EARTHWORMS [Jan. 14, Dr. Michaelsen has also called attention to the variability of the genital papillae. Of m y specimens four are normal (i. e. there are 3 pairs on vii., viii., ix.); in two the papillae are on vii., viii. on one side of the body, on viii. only on the other; in the seventh specimen these conditions are exactly reversed; in the eighth, one side of the body is normal, on the other the papillae he on viii., ix., x. In six specimens from Mauil the genital papillae and prostates were as follows :- 1. . .. On vii., viii. 0. 2 0. Small. 3.. .. viii., ix. 0. 4. . . . On viii. (left side only). Small (on one side only, left). 5.... 0. 0. 6. . .. vii., viii. Small (on one side only, left). It is interesting to contrast this list with the last, on the hypothesis, of course, that the islands upon which the two series were collected are different. There were also two individuals from Mauna Loa, Hawaii, upon which I do not comment, as there were only two. Perichaeta perkinsi, n. sp. The length of this species (of which I have examined two examples) is 192 m m . ; the diameter is 6 m m . The number of segments is 110. The colour is of a light brown, darker on the back. The prostomium is broad (2*5 mm.) but not long; it is cut off from the first segment by a transverse groove. The buccal cavity is eversible, as in many Perichcetce. The first dorsal pore that I could detect lies between segments xii./xiii. The clitellum occupies the whole of segments xiv.-xvi., and is without setae. The oviducal pore, distinctly a single pore, is situated in the middle of a white area upon the brown clitellum on segment xiv. The male pores are rather wide apart, and upon segment xviii. I counted eleven setae between them. Each pore itself is upon a whitish papilla, and to the outside is another smaller papilla which is not perforated; the two are surrounded by several concentric circular wrinkles of the integument. There are no genital papillae except the one just referred to and upon which open glands. The setce of P. perkinsi are not so numerous as in many other species. The segments in the anterior part of the body have fewer setae than those which follow. There is a gradual increase up to the xviith segment, whence the number appears to remain fairly 1 Mr. Perkins has queried the locality. |
