Plate XIV. 



Abatus cavernosus Piiu.. 

 I'. 20, -'b, 4(), 74. 



Fig. 163. A young specimen, measuring 2,3 mm., taken out of one of the deepened jietala by the late Pro- 

 fessor Peters of Berlin. It is jejune, astomous, aproctic. Ventral view. 



Fig. 1G4. The same, dorsal view. 



Fig. 164, A. The calycinal region. 



Fig. 165. The buccal membrane, entire, unpierced, tlie oesophageal end of the alimentai'y canal with its lumen 

 appearing on its inside. To be compared with the woodcut p. 26, representing the same parts 

 in a specimen a little more advanced, in which the oesophageal opening has pierced the buccal 

 membrane centrally. 



Fig. 166. The calycinal region from the inside, sho\. ng the blind excretory extremity of the intestine touching 

 the closed membrane centrally. 



Fig. 167. The peristomal region from the inside, showing the blind oesophagus resting against the buccal 

 membrane. 



Fig. 168. The blind excretory end of the intestine, suspended to the peritoneal lining. 



Fig. 169. A spherid, optica! section. 



Fig. 170. A tubercle. 



Fig. 171. A spine with the larval envelope. 



