| OCR Text |
Show 374 MR. F. E. BEDDARD ON THE [Apr. 19, The male generative pores are related to the ventral pair of setae, and are situated upon the 17th segment. In the position of the reproductive apertures the present species agrees with all the other species except E. decipiens, where the female pores are upon the 12th segment. § Integument. The epidermis is covered, as in other Earthworms, by a delicate cuticle ; the cells of the epidermis are of two kinds, (1) tall columnar cells, (2) oval glandular cells (Plate XXXIII. fig. 14,6): these resemble exactly the epidermic cells of other Earthworms. In one particular the epidermis of Eudrilus differs from Lumbricus, and the majority of other genera of Lumbricidse, and agrees with Urochata, a genus with which it does not show any other marked resemblances. Between the setae on all the segments of the body is a row of peculiar structures, which appear from the investigations of Vejdovsky to represent degenerate or abortive setae; they consist in each case (fig. 14, a) of a small spherical body darkly stained by borax carmine, which is lodged in an invagination of the cuticle. The cuticle, however, instead of forming a single layer round the central body, is split into a number of layers like the coats of an onion ; flattened deeply stained nuclei are situated between these layers. These structures are also found upon the clitellum, and they invariably lie at the base of the epidermis, just above the circular muscular layer. The structure of the clitellum is precisely similar to that of Lumbricus. The circular muscle-layer resembles that of other Earthworms ; numerous pigment-granules lie between the individual fibres on the dorsal side of the body. The longitudinal muscular coat shows the bipinnate arrangement of its fibres which Claparede l was the first to describe in Lumbricus. This fact is worth mentioning, inasmuch as it is unusual in Lum-bricidae ; in by far the majority of instances the longitudinal muscle-layer does not show this bipinnate arrangement. I should remark that in the anterior region of the body, Eudrilus does not show the characteristic bipinnate disposition of its fibres. § Alimentary System. The most interesting feature about the alimentary canal relates to the calciferous glands, which are, in many respects, rather different from those of other Lumbricidae. The other subdivisions of the alimentary tract are of no special interest, and do not differ materially from those of the more typical genera, such as Perichata. I may state that I have not observed any traces of a typhlosole ; the absence of this structure, which is generally present in Earthworms, allies Eudrilus to Pontodrilus. Nor are there in the present species intestinal glands such as those which are characteristic of Eudrilus 1 Zeitschr. f. wiss. Zool. 1869. |
