226 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
in the female. It ends in a slender, upturned process termed the 
egg-guide, which lies between the ventral valves of the ovipositor. 
The ninth and tenth terga are very short and fused together. 
They are marked by a deep transverse suture except on the 
lateral margins. Behind them dorsally is a median, convex, 
somewhat triangular supra-anal or suranal plate. This covers 
the dorsal edges of a pair of podical plates whose ventral margins 
are continuous with those of the fused ninth and tenth tergites. 
Inserted in the sutures between the bases of the podical plates 
and the tenth tergite is a pair of small elongate-triangular 
appendages with free tips, the cerci (singular cercus). These and 
the valves of the ovipositor are regarded as true appendages of 
the abdomen, homologous with the legs. 
The male is the smaller in size and its abdomen is of a quite 
different form and somewhat upturned apically. The eighth 
sternum is no longer than the lower margin of its corresponding 
tergum; the ninth sternum is large, extending beyond the tenth 
tergum, and bears apically a large, bluntly conical suhgenital 
plate, which terminates the abdomen. The membrane covering 
its dorsal part is called the pallium. The ninth and tenth terga 
are similar to those of the female. The supra-anal plate is acute 
at apex and bears midway of its length a prominent sinuate trans- 
verse carina; the cerci are a little longer than in the female. In 
some Locusts the hind margin of the tenth tergum of the male 
bears in the middle a backwardly directed forked projection or 
process, the furcula; in others this may be reduced to a pair of 
tubercles on the hind margin of the tergum or entirely lacking 
as in this species under discussion. The form of the various 
parts at the end of the abdomen, particularly of the cerci, supra- 
anal and subgenital plates, is often of great value in distinguishing 
species (see Plate 22). 
Internal Anatomy. 
The internal anatomy of the Orthoptera is relatively of so 
little importance to persons interested simply in their natural 
history that it may be passed over here very briefly. It is in 
general similar to that of other types of insects. The food-canal 
extends from mouth to anus, its parts varied in accordance with 
the work they have to perform: the grinding of the food is done 
