EXPLANATION OF PLATES. 



PLATE VII. Digestive Organs of Mersatorial Birds. 



Fio. 1. Ligestive Organs of Wilson's Storm-Petrel, Thalassidroma Tf'ilsom. 



a, oesophagus. 



b, c, provcntriculus, enormously di- 



lated. 



d, stomach, extremely diminutive, and 



directed forwards. 

 d, e,f, duodenum. 

 <7, rest of intestine. 



Fig. 2. Digestive Organs of the Common Gidl, Lams canus. 



c. b, c, oesophagus. 

 b, e, proventriculus. 



d, stomach. 



d, e,f, duodenum. 



a, b, c, 



b, c, cloaca. 

 d, stomach. 



d, e,f, duodenum. 



g, rest of intestine. 

 h, cccca. 

 i,j, cloaca. 



Fig. 3. Digestive Organs of Lestris. 



g, rest of intestine. 

 h, cceca. 

 i, j, cloaca. 



