| OCR Text |
Show 1906.] ANATOMY OF CENTROPHORUS CALCEUS. 8 7 3 portion of the stomach, so that the condition found in Centrophorus calceus seems to be unique. Owing to this fact that the bile-duct opens into the large intestine and not into the elongated portion of the duodenum, there is obviously no " Zwischendarm " or small intestine* present in Centrophorus calceus as in the other three Squalidse referred to. As regards the position of the pyloric thickening in the gut of C. calceus, I regret not being able to speak with certainty. Usually it occurs at the commencement of the duodenum, i. e., anterior to the opening of the bile-duct, and there certainly is a thickening in that position in C. calceus, but it is not very distinct. There are no pyloric caeca present in C. calceus such as occur in Lcemargus. Centrophorus calceus. Text-fig. 1 3 5- Transverse section across bile-duct (O-P of PI. LV II. fig. 3). Letters as before. Text-fig. 136.-Transverse section across bile-duct (Q-R of PI. LV II. fig. 3). " Letters as before. The bile-duct has here divided into two. The internal surface of the cardiac portion of the stomach is quite smooth and devoid of glands; on the other hand, the internal surface of the pyloric portion is folded into longitudinal ridges and highly glandular (text-figs. 128, 129). Transverse sections across the duodenum about half an inch from its commencement (text-figs. 130, 131), and about an inch from its Text-fig. 135. Text-fig. 136. B * I am indebted to Dr. G. J. Jenkins for some information in this connection. 58* |
