114 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 8l 



The channels on the walls of the preoral cavity that lead into the 

 mouth are continued upon the inner w^alls of the anterior pharynx. 

 The median epipharyngeal groove proceeds upward on the anterior 

 pharyngeal wall between two converging ridges, but it soon ends 

 in a thick median fold which follows the midline of the roof of the 

 posterior pharynx to the end of the latter. Likewise, the median 

 channel leading upward from the base of the hypopharynx is con- 

 tinued on the rear wall of the anterior pharynx, between two con- 

 verging ridges, and ends in a median ventral fold on the floor of the 

 posterior pharynx. From the lateral angles of the mouth, wide chan- 

 nels go dorsally in the side walls of the anterior pharynx, but these 

 again end each in a lateral fold of the posterior pharynx. Thus the 

 relative positions of the principal ridges and grooves in the walls of 

 the two parts of the pharynx are reversed. In the posterior pharynx 

 there is a slenderer intermediate fold between each two of the major 

 dorsal, lateral, and ventral folds. These eight folds of the posterior 

 pharynx end at the entrance of the crop, giving the aperture a stellate 

 appearance when seen from the lumen of the crop. All the pharyngeal 

 folds, except the midventral fold of the posterior pharynx, are clothed 

 with hairs directed backward. 



In the crop, a wide dorsal channel proceeds from the pharyngeal 

 opening posteriorly on the anterior third of the upper wall between 

 converging folds of the intima. A narrower ventral channel follows 

 the midline of the floor between a pair of folds that diverge posteriorly 

 and are lost beyond the middle of the organ. The lateral walls of 

 the anterior half of the crop are closely corrugated by obliquely trans- 

 verse ridges, which bear rows of small, slightly curved, sharp-pointed, 

 chitinous teeth projecting backward. The anterior three or four 

 transverse ridges on each side are particularly conspicuous by reason 

 of their greater width, and because they are thickly beset with similar 

 but slightly larger teeth than those of the other ridges. In the posterior, 

 narrowed part of the crop the transverse ridges are replaced by fine, 

 parallel, lengthwise folds, following the lines of the longitudinal 

 muscle fibers. Numerous teeth are present here also, but they are 

 smaller and blunter than those of the anterior region, and are mostly 

 arranged in small groups, usually two or three together, on elevations 

 of the intima along the folds. The interior characters of the crop are 

 better developed and the teeth are more numerous in the larger organ 

 of the female grasshopper than in that of the male. They can be 

 studied best on pieces of the intima stripped from the tough muscular 

 sheath of the crop. 



