OCR Text |
Show 1885.] MR. R. COLLETT ON ECHIDNA ACANTHION. 153 side, yet here mixed with normal hairs. At the hind margin of the ear is found a thick patch of blackish hairs, as in the other species. The belly is covered with hairs, longer or shorter, mixed with flattish bristles ; on the breast and lower side of the head there are, as a rule, no bristles, but hairs only. Colour.-The dorsal spines are pale yellowish with black tips ; this black tip is very short in the longer spines, but broader in the shorter ones, by which the longer get a clearer appearance than the rest. In some specimens (but not in all) one or two of these spines are entirely yellowish without black tips. In the shorter spines the pale colour at their bases is almost hidden by the black. Thus, contrary to E. aculeata, where all spines are equally coloured (yellowish with short black tips), and almost of the same length, E. acanthion at a distance appears to be blackish with irregular series of long and clearer-coloured spines. On the nape and the front the spines are sometimes entirely black, sometimes yellowish, or particoloured. One of the specimens (No. 9) differs a little from the rest, the longer spines here being almost black, like the shorter. This specimen, a full-grown female, therefore appears to be blackish with a few yellowish spots. The colour of the belly is blackish brown, under the tail perfectly black ; in some specimens a paler line m a y be observed on the outer side of the legs. The young male (No. 1) is somewhat different from the rest, the breast and throat being reddish brown, which colour also extends itself along the inner side of the fore limbs, and can be traced also on the hind limbs. An irregular black band crosses the throat from the lower side of the ears. The belly is blackish brown, as in the other specimens, and mixed with one or two yellowish spines. Skeleton.-In the young male, with a total length of 365 millim., the skeleton is very far from being perfectly ossified. A large fonta-nelle is found on the upper part of the os temporale ; in many of the bones the different epiphyses are not yet grown together. There are open sutures between the occipitals, and between the costce cervicales and their vertebra?; the caput femoris is separate; the sacral vertebrae are all separate, as well as the bones of the pelvis. On the dorsal vertebrae the spinous processes are very cartilaginous ; the same is the case with the upper margin of the scapula, of the proc. olecranoides in the fibula, and at the ends of other bones. The os coracoideum is separate On the lower jaw the proc. coronoideus ext. is still not developed. In an apparently almost full-grown female, with a total length of 425 millim., the sutures are still open around the os basioccipitale, and the costa cervic. of the epistrophaus can still be separated when slightly pressed, and the epiphyses both on the ulna and radius and on the fibula and tibia may be easily parted \ 1 As mentioned above, all these parts are perfectly ossified in a specimen of E. aculeata of the same size. |