1918] Thoracic Sclerites of Dissosteira 363 



In his Fig. 89 of the locust Melanoplus, which has been 

 copied in many textbooks and other pubHcations, Packard, 

 1898, restricts the term coxa to the anterior region of the coxa 

 ("CX2" of Fig. 1 of this paper) and terms its posterior portion 

 the "trochantine," in the pro- and mesothorax of the grass- 

 hopper, although the true trochantin "tn" (or what is left of 

 it) is present. In the metathorax of his figure of Melanoplus 

 Packard interprets the anterior region of the membranous area 

 above the coxa "cxs" (Fig. 1) as the "coxa" and the posterior 

 region of this membranous area he designates as the "tro- 

 chantine." The true metathoracic coxa "cxs," he calls the 

 trochanter. 



The Sternal Region. 



Jordan, 1902, in his Fig. 7 of Acridium terms the ventral 

 portion of the anterior marginal region "pr2" (Fig. 2 of this 

 paper) the " mesoclidium " in the mesothorax of the grass- 

 hopper, and designates the lateral portion of this marginal 

 region as the "peristernum." The term "sternum" is restricted 

 to the portion of the sternum behind the region "pr2" by 

 Jordan, who applies the term "sternite" to the ventral and 

 entire lateral region of the segment. 



Snodgrass, 1909, in his Fig. 70, of the mesopleuron of 

 Dissosteira, terms the region "pr2" (Figs. 1 and 2 of this paper) 

 the "pre-episternum," but the " pre-episternum " of his Fig. 56 

 of Melanoplus, and Fig. 57 of Ilippiscus is an eritirely different 

 sclerite, namely the region "Iss" of Fig. 1 (of this paper). 

 Snodgrass, 1910, designates a region which for all practical 

 purposes corresponds to the region "pr2" (Figs. 1 and 2) as the 

 "prepectus" in the Hymenoptera, but he claims that the 

 "pre-episternum" is not present in the Hymenoptera. This is 

 apparently due to the fact that he has applied the term "pre- 

 episternum" to so many different sclerites in his earlier paper; 

 but since the region which he calls the prepectus in the Hymen- 

 optera is located in the same position as the sclerite which he 

 designates as the "pre-episternum" in the grasshoppper 

 Dissosteira, and extends into the sternal region in the same 

 way {i. e., sclerite "pr2" of Fig. 1), it would appear that Snod- 

 grass is mistaken in concluding that the "prepectus" of Hymen- 

 optera is not to all intents and purposes homologous with the 

 sclerite "pr2" (F'igs. 1 and 2) which he terms the " pre-epister- 



