OCR Text |
Show 1885.] MR. R. COLLETT ON ECHIDNA ACANTHION. 159 other bones of the limbs can scarcely be shown to exist, but all perceptibly stronger in E. aculeata. As mentioned above, E. acanthion is furthermore distinguishable from E. aculeata (and setosa) by the claws of the hind foot, the third claw reaching hardly the half of the length of the second, whilst in the other species these claws are of nearly the same length. A corresponding difference in the strength of the respective phalanges may be observed. Finally, with regard to the skull it has been already stated that in most respects it agrees almost perfectly with that of E. aculeata. Certainly the length is a little greater in the latter species(116 millim.) than in E. acanthion (111 millim.); this, however, may perhaps not always be the case. The shape of the skull, as seen from behind, appears to be to a certain degree varying in both species ; but E. acanthion seems constantly to have a narrower cerebral area than E. aculeata. As mentioned above, Dr. Murie has described in the Journ. of Linn. Soc. vol. xiv. (p. 413) a skull of the species, found by Capt. Armit at Cardwell, thus not far from the York peninsula. In his comparison of the skull with five skulls of Echidnce from S. Australia and Tasmania, he states that it is " barely appreciably narrower across the cerebral area, but decidedly lower in the same region." This feature is characteristic in all the examined skulls of E. acanthion, and is still more perceptible in the younger specimens than in the full-grown. Thus the greatest breadth of the skull is below the foramen retro-temporale, whilst the part above gradually decreases upwards ; in the full-grown specimens (No. 3 and No. 9) this decrease is less marked, but the skull is never broader above the said foramen than below, as in E. aculeata. In the latter species the os temporale widens upwards (in the two skeletons preserved in the University Museum of Christiania), and the greatest breadth of the skull is therefore immediately above the foramen retro-temporale, not below it. Finally, the snout is straight in E. aculeata (in the specimens before me), but in all specimens of E. acanthion more or less bent upwards. Comparison ivith E. lawesi.-In March 1877 Mr. E. P. Ramsay, in Proc. Linn. Soc. New South Wales (vol. ii. p. 30), described an Echidna under the name of Tachyglossus laivesi from a specimen just received from Port Moresby in New Guinea. The type specimen was a skin of a male, which Ramsay considered to be full-grown ; its length from the snout to the tip of tail was 13-4 inches, or about 336 millim. In Sept. 18/8 Mr. Ramsay gave a short communication in the same Journal (vol. iii. p. 244) on three more specimens, also from the S.E. coast of N. Guinea. The new specimens consisted also in the dried skins only, and the measurements given in the same place may therefore also be considered as but approximative. The largest specimen had a length of 16 inches from snout to root of tail, and when the length of the tail is added, the total length has been about |