156 CALIFORNIA ACADEMY OF SCIENCES. 



more to one side of the oesophagus than to the other. 

 The alimentary canal of Eurymetopus taurus may be 

 taken as a type of this latter form (plate xi, fig. 11). 

 The oesophagus is a long, slender tube reaching from the 

 head to the mesothorax. Here it enters the anterior 

 dorsal aspect of the crop. The latter lies dorsal and to 

 the left of the other organs of the body-cavity except 

 the heart, and extends from the middle line backwards 

 and to the left, reaching the sixth abdominal segment 

 when considerably distended. Its size and shape vary 

 according to its contents, but it is generally much 

 longer than wide, rounded in front, swollen toward the 

 middle, and tapering behind. Its upper end extends 

 a short distance beyond the opening of the oesophagus 

 into it. About opposite the latter point, on the ventral 

 aspect of the crop, the subingluvial part of the oesoph- 

 agus begins and runs backwards to the ventriculus, 

 forming a short, narrow tube. The ventriculus is 

 smaller than the crop when the latter is fully distended. 

 Anteriorly it bears two large, lobular cseca, each being 

 rather flat and expanded beyond its base. The stomach 

 lies with most of its long axis in an antero-posterior 

 direction. It is widest through the middle; in front 

 of this it is slightly constricted, while in the opposite 

 direction it becomes very much narrowed, and, assum- 

 ing a tubular form, makes a bend to the left. It goes 

 a short distance in this direction and then meets the 

 hind-gut. The latter turns immediately backward and 

 runs in a straight line to the exterior. It is divided 

 into an anterior, narrow, prerectal part and a posterior, 

 enlarged rectum. The former bears at its anterior end 

 the four Malpighian tubules, becomes enlarged toward 

 its middle, and is separated posteriorly from the rectum 

 by a slight constriction. The latter is much distended 



