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Show 1886.] MR. F. E. BEDDARD ON A LARGE EARTHWORM. 175 by the clitellum, but to differ from both this and A. obtusus in the position of the male generative pores. The genital seta; of the 17th and 19th segments are almost exactly like those of A. ungulatus, but the prostate glands, as in A. obtusus, are cylindrical coiled tubes and not multilobate glands as in A. ungulatus ; at the same time the prostate glands in several examples of my species are so closely coiled that they present an appearance which might easily be mistaken for that which has been stated by M . Perrier to be characteristic of A. ungulatus ; it is just possible that the condition of the specimen dissected by M . Perrier may be responsible for the lobed appearance of the prostate glands. Another difference between my species and A. ungulatus is in the spermathecae, which can hardly be said to have a diverticulum, and are in segments 8 and 9, not 8 and 10. The structures lying between the two spermathecae of each side may, as I have already suggested, be identical with that described above, but evidently differ in detail. The most important difference between the species described here by myself and those of M. Perrier is undoubtedly in the position of the male generative pores ; in so many species-in fact in all except A. obtusus, A. verticillatus, and A. ungulatus-the male generative pores are upon the 17th and 19th segments1. EXPLANATION OF PLATE XIX. Fig. 1. Acanthodrilus layardi; anterior region of body, dorsal aspect. 2. Segments 13-20, from ventral side, to show position of female generative pores upon 14th, and the male generative pores upon 17th and 19th segments. The clitellum is indicated by shading. 3. Genital spicule from segment 8, magnified. 4. The lower extremity of the same, more highly magnified. 5. Spermatheca; and accessory genital glands: cp, spermathecae ; v, ventral blood-vessels giving off branch to the spermatheca ; a corresponding branch is also given off from lateral heart; s, sac containing modified seta; (figs. 3, 4 ) ; g.b, glandular bodies opening in common with seta sac ; n, glandular tufts of nephridium ; n', duct of nephridium. 6. Anterior region of body dissected : cp, spermathecae; n, nephridia. 7. Principal vascular trunks of anterior region : d, dorsal vessel; sn, supra-intestinal ; v, ventral; I, lateral; h, '• hearts." 1 Referring to m y paper already quoted upon the New-Zealand species of the genus, I find that the male generative pores are there stated to be upon the 16th and 18th segments. A reexamination of the specimens has convinced me that that statement is wrong, and that they are, as in the present species, upon the 17th and 19th segments, while the spermatheca; are in the 8th and 9th segments as indicated in the woodcut (P. Z. S. 1885, fig. 1, p. 815). Should the specimens to which the present note relates prove to belong to a distinct species from either of those described by Perrier, I propose to term the species Acanthodrilus layardi. |