162 DR. 0. F. SONNTAG OX THE 



The relative positions of these divisions are different in 

 B. tridactylus and B. cucuUiger. The reader is referred to the 

 works of Rapp (10), Klinckowstrom (6), and Oppel for descrip- 

 tions of the latter. Kliuckowstrom's paper is the best, for it is 

 profusely illustrated. Moreover, there is an excellent specimen 

 of the stomach of B. gularis in the Museum of the Royal College 

 of Surgeons. Klinckowstrom described the histology. 



When the stomach of B. tridactylus is examined from the 

 ventral aspect (Plate II. A), one sees the paunch (Plate II. A, c) 

 posterior and to the left ; the cardiac stomach (Plate II. A, d) 

 anterior and to the right ; and the ventral part of the pylorus 

 (Plate II. A, h) lying most to the right. The entire pylorus is 

 not visible on the ventral surface as in B. cucuUiger. When the 

 stomach is viewed from the right, one sees the U-shaped pylorus 

 consisting of dorsal and ventral limbs, and a posteriorly-placed 

 bend (text-fig. 14 A, py). The dorsal limb emerges from the 

 cardiac stomach, and the ventral limb communicates with the 

 duodenum. In B. cucuUiger the limbs are anterior and posterior 

 with the bend to the left. When the stomach is viewed from 

 the dorsal aspect, one sees the paunch posterior, the cardiac 

 stomach anterior, and the dorsal limb of the pylorus to the right. 

 The U-shaped pylorus is seen in Plate II. B 3. 



The simple, conical, csecal appendage of B. tridactylus is longer 

 and more slender than in B. cucuUiger. Its position may vary, 

 but in my specimen it first passed from the posterior and right 

 part of the paunch to the right. It was then recurved on itself, 

 and its apex rested on the cardiac stomach. It is also more 

 slender than in Cholcepus. 



No author has described the peritoneal sheet connecting the 

 CEecal appendage to the paunch (Plate II. A. b). This is triangular, 

 and fills up the space between them. Its apex lies along the 

 anterior border of the appendage, and there is a sharp free 

 border looking forwards and to the light. The right gastric 

 vessels run between its layers as they separate to surround the 

 appendage (Plate II. A, j). 



The right gastric artery reaches the ventral surface of the 

 stomach to the right of the oesophagus and passes posteriorly and 

 to the right. It ends about the middle of the c?ecal appendage. 

 It is accompanied by the right gastric vein, and all the gastric 

 tymphatic glands lie alongside it. 



Rapp (10) and Klinckowstrom (6) have described the internal 

 structure of the stomach of B. cucuUiger, and that of B. tridac- 

 tylus agrees with it in most points. Their accounts, however, 

 can be amplified in several ways. Speaking generally, the cardiac- 

 stomach has a mechanical function, the paunch and appendage 

 are secretory, and the pylorus has both properties. 



The division between the paunch and cardiac stomach is 

 marked by a strong, thick ridge (Plate II. B, a) and a second 

 ridge into which the point of the pin is inserted, corresponding to 

 the white line seen externally on the ventral surface. It marks 



