26 



THE COAL MEASURES AMPHIBIA OF NORTH AMERICA. 



If it were not for the fact that the oesophagus became loosened and dropped 

 from its place shortly after death, the alimentary canal would be in place and would 

 immediately recall a freshly dissected specimen of a recent salamander. The ante- 

 rior end of the oesophagus lies obliquely across the chest region with its tip pointing 

 slightly downward. The length of the oesophagus proper, in one specimen, is only 

 about 3 mm. As it is preserved, the oesophagus lies in a semi-sigmoid curve with the 

 convexity anterior, and enters the cardiac portion of the stomach by a gradual con- 

 striction. The stomach is clearly preserved as a distinct sac-like organ with two 

 lobes which correspond to the cardiac and pyloric limbs. It measures about 7 mm, 

 in length by 2 mm. in its greatest diameter. The muscular 

 constriction which divides the organ into pyloric and cardiac 

 divisions occurs at a distance of 4 mm. from the upper end. 

 The pylorus is designated by a rather pronounced constric- 

 tion which may be partly accidental, although it recalls the 

 pylorus of modem frogs. From this constriction, which lies 

 on the left side of the fossil, as it is preserved, the duodenal 

 portion of the intestine makes a straight course posteriorly 

 to near the anal region, where it takes a sharp bend and 

 curves back to run parallel with itself for the distance of 

 4 mm. In its upward course the intestine enlarges, and 

 practically the same enlargement continues throughout the 

 remainder of the course to the anus. At a distance of i 

 mm. from the anal end, the rectum dilates probably 0.125 

 mm. to form the cloaca. After the intestine has continued 

 its parallel course for the 4 mm., as above stated, it turns 

 abruptly to the right for a distance of 2 mm. It then runs 

 posteriorly for a short distance, then bends back and under 

 itself to again make a double sigmoid curve, when at a dis- fig. 7. 

 tance of 6 mm. from the anus it assumes a straight course, 

 which it continues to the end. 



The anus lies at a level which is approximately that of 

 the lower end of the femur, which is preserved as an impres- 

 sion on the left side of the fossil, thus agreeing in its position 

 with that found in modem Caudata. Lying inside the curve 

 of the stomach and partly inclosed by the oesophagus is a smooth area which may 

 possibly represent the impression of some of the accessory digestive glands, such 

 as the liver. Occurring in this smooth area are numerous fine lines which possibly 

 represent the impressions of blood-vessels; but they are so imperfectly preserved 

 that one can not be sure. 



Representatives of several genera of the modem Caudata have been dissected 

 in order to make a direct comparison of the fossil alimentary canal with that of the 

 recent forms. The alimentary tract of Desmognathus fuscus Raf . from the vicinity 

 of Ithaca, New York, resembles in a marked degree that of the fossil form. The 

 nearest approach to the condition there represented is found, however, in an imma- 



Alimentary canal of a 

 Coal Measures salamander as 

 illustrated by the smaller speci- 

 men of Eumicrerpeton parvum 

 Moodie, from the Mazon 

 Creek shales. X 3. Original 

 in Yale University Museum. 

 a, anus; dd, duodenum; in, 

 intestine; /, impression of 

 liver(?); oes, oesophagus; st, 

 stomach. 



