134 



REPORT OF STATE GEOLOGIST. 



S.V 



"notched," etc. llie surface of the disk is often smooth, but some- 

 times "wrinkled" and may be "rugose'' or roughened with numerous 

 tubercles. 



The under or "ventral" side of the protliorax is a narrow, some- 

 what movable piece called the prosternum. On its center it often 

 bears a tooth or spine (pro sp.), the presence 

 or absence, and shape of which form charac- 

 ters used in classification. Near the outer ends 

 of the prosternum are shallow sockets in which 

 are attached the Iront pair of legs. 



The IMesothorax and Metathorax, the 

 second and third segments of the thorax, arc, 

 in the locust. ratluT iinnly united with the 

 basal abdominal segment of the abdomen to 

 form a firm walled l)o.\; though in the Blatluhn 

 they are distinct. The upi)er portion of tliese 

 segments is, in many Orthoptera, partly or 

 wholly covered by the pronotum. To the 

 mesothorax are attached the first oi- outiT ])air 

 of wings and the second or middle ])air of legs. To the metathorax 

 are joined the inner wings and the third or hind pair of legs. The 

 under or ventral portion of these segments are called respectively 



Kp.-: 



Fig. 7. Showing "pro 

 zona" and " metu/.ona " 

 of i)ronotum, and " scu 

 tellum " of vertex. 

 (After Lugger.) 



Fig. 8. 



Lower or ventral view of the thorax of a locust. 

 (After Luu'ger.i 



the "mesosternuiu" and "metasternum." '['\\v tormer, in the locust, 

 is composed of a front transverse portion, with two nearly rectangu- 

 lar lobes projecting baekward. Between these lobes is dovetailed 



