OCR Text |
Show 1875.] MR. E. R. ALSTON ON THE GENUS ANOMALURUS. 93 The stomach is perfectly simple and nearly oval, the cardiac and pyloric openings being near one another. The walls are very thin ; and the epithelial lining is smooth and perfectly uniform throughout. A very small external fold or pucker runs transversely across the lesser curvature. In A. fraseri the greatest diameter is 1*75 inch, the lesser about *80. The duodenum has the usual dilatation below the pylorus; the length of the small intestine in A. fraseri is 43*50 inches, and in A. pelii 60 inches. The caecum is of considerable volume. In A. fraseri its length is about 5 inches, and its greatest diameter *50 ; in the specimen examined of A. pelii its proportions were similar, but it was too greatly injured by shot to allow of exact measurement. In form and structure it is very different from that of the Squirrels, and, indeed, from that of any of the Glires Simplicidentati with which I am acquainted. It is at first continuous with the colon, irregularly coiled on itself, and sacculated almost to its end by an internal spiral fold, with a free inner edge, as in the Hares; this fold is nearly regular and continuous, but here and there it is interrupted. The extremity is very narrow, perfectly simple, and abruptly reflected on itself. In the figure the caecum is shown uncoiled and extended, in which condition its structure is more plainly shown than when it is in its natural convolutions. The colon is at first marked by the inner fold continued from the caecum; its first loop after leaving the latter is longer than the second. The length of the large intestine from caecum to anus is in A. fraseri about 16 inches, in A. pelii 47 inches, making the whole length of the intestine about 60 inches in the former and 107 inches in the latter, or rather more than five times the length of the head and body in each case. Fig. 3. Liver of A. fraseri, natural size. LL, left lateral lobe; LC, left central; RL, right lateral; RC, right central; s, Spigelian ; c, caudate lobe. |