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Show 678 DR. WATSON ON D A S Y P U S SEXCINCTUS. [June 18, by the junction of the two crura alone, and possesses neither bulb nor glans. With regard to the other muscles of the penis, these closely resemble those already described in Chlamydophorus, with this difference, that the single mass formed by the bulbo-cavernosi muscles in the latter are here represented by two distinct and powerful fleshy bands which envelop the under surface of each crus previous to its junction with its fellow. The testicle differs in position in Dasypus from that which it occupies in Chlamydophorus, being attached to the inguinal region of the anterior abdominal wall in the former, whilst in the latter it lies behind the kidney. The globus major in Dasypus is closely applied to the anterior extremity of the testicle, and does not form the looplike arrangement seen in Chlamydophorus. The vasa deferentia in both are non-convoluted; nor is there any trace of vesiculee seminales in either. In both, a prostate and Cowper's glands are present, the former being traversed by the vasa deferentia in their course to the urethra, whilst the latter, although occupying the same position, are relatively considerably smaller in Dasypus than in Chlamydophorus. The bladder and urethra are similar in both genera, the only difference being that the walls of the intrapelvic portion of the latter are much more muscular in Chlamydophorus than in Dasypus, and that in the latter a well-marked caput gallinaginis, of a pyramidal form, is present, which is not represented in the former. In neither is there any trace of a vesicula prostatica. It will thus be seen that in respect of the male sexual organs the resemblance between Chlamydophorus and Dasypus sexcinctus is very striking-a resemblance which, in respect of other organs, has been already pointed out by Prof Garrod 1. As shown by that anatomist, Chlamydophorus agrees also with Tolypeutes and Xenurus in the absence of vesicula? seminales and the simple condition of the glans penis, in both of which respects it differs from Tatusia. The presence of Cowper's glands constitutes a further element of agreement between Chlamydophorus on the one hand, and Dasypus and Xenurus on the other. These glands are also present, according to Dr. Murie2, in Tolypeutes; but whether in Tatusia I cannot say, as with regard to the latter we possess no precise information. So far, then, as the observations above recorded go, they tend to strengthen the conclusions already arrived at by Mr. Garrod upon other grounds with regard to the close relationship which exists between Chlamydophorus and Dasypus. Professor Macalister, as the result of his elaborate investigation into the muscular anatomy of the Edentata, arrives at the conclusion that " the position of Chlamydophorus will be seen to be plainly among the Dasypodidee, and very close to Tatusia." The arrangement, however, of the sexual organs, including the nipples, together with that of the alimentary canal, which in Dasypus and Chlamydophorus is provided with two colic caeca, these last being absent in the other genera above referred to3, appear rather to point to a closer relationship between Chla- 1 P. Z. S. 1878, p. 222. 2 Trans. Linn. Soc. vol. xxx. 3 See Prof. Garrod's paper. |