26 PROCEEDINGS OF THE ACADEMY OF [Jan., 



(the prothoracic sternal laterale) and one of the cervicals with the meso- 

 thoracic episternal laterale of the same specimen. The remaining scle- 

 rites of the posterior lateral cervicals (CS 2X ) he homologizes with the 

 sternal laterale of the mesothorax. Borner likewise considers that the 

 mesothoracic sternal laterale (pi. II, L" 2 ) and episternal laterale (L'\) 

 are subdivisions of the antecoxal laterale (pi. Ill, Lb). These views 

 however seem quite untenable. 



The longitudinal division of the laterale into the anterior and ante- 

 coxal regions is best shown in the cockroach (pi. Ill), although it is 

 clearly traceable in a number of insects. In many Neuroptera, as for 

 example Corydalis (fig. 17), Chrysopa (fig. 3), etc., the antecoxal 

 laterale appears as a narrow strip (Lb) connecting the katepimeral 

 complex 9 (Esk X ) with that portion of the sternum which will be later 

 spoken of as the furci-sternum (S 3 ). The anterior laterale (L a ) is 

 usually quite large, filling the region between the episternum and the 

 "Basi-sternum" (*S> 2 ). 



In the thorax of Gryllus, Voss, '04, has described a sclerite which 

 seems to correspond in part to the laterale. He terms this sclerite the 

 coxosternum, upon the ground that it represents the region so desig- 

 nated by Borner, '03. This homologizing, however, is quite incorrect, 

 for, as may be readily seen in his figures, Borner's "coxosternum" 

 includes the epimeron, episternum and laterale. Furthermore, Ver- 

 hoeff had long before employed the term "coxasternum" to designate 

 the fusion product of the coxae with the sternum. The laterale, there- 

 fore, can hardly be termed the " coxosternum. " 



The Trochantin. — The small, somewhat triangular-shaped sclerite 

 articulating with the coxa is designated as the trochantin, trochantine 

 or trochantinus. In the Blattidse (fig. 21 and pi. Ill) the trochantin (T) 

 is quite large, and in some species it is united for a short distance with 

 the episternum. In the Trichoptera (fig. 18) it would appear that the 

 trochantin has fused with the katepisternal complex almost completely, 

 its extreme tip alone remaining free. The trochantin may thus com- 

 pletely fuse with the katepisternal complex, or, according to certain 

 ■coleopterologists, it may fuse with the coxa. 



In the prothorax of all the Blattidse that the writer could obtain 

 the trochantin is transversely divided into two regions, the larger of 

 which may be termed the trochantinus major and the smaller one the 

 trochantinus minor. This condition seems to be a characteristic of 

 the Blattidse alone, and may prove to be of systematic value. 



8 I.e., fusion product of the katepimeron, part of the trochantin, and a portion 

 ■of the antecoxal laterale. 



