Vol. XXV] ENTOMOLOGICAL NEWS 23 



The lateral intersegmentals are the interpleurites, Ip (Figs. 

 2, 3, 4 and 5), and the postcoxale, Poc (Fig. 4) might possibly 

 be likewise included under the designation lateral intersegmen- 

 tals. There are two well developed interpleurites in front of 

 the pleuron of the mesothorax in Corydalis. The posterior 

 one is much the larger, and probably belongs to the segment 

 behind it, while the anterior one may belong to the segment 

 in front. The anterior interpleurite in this insect bears an 

 internal process for muscle attachment. The interpleurites Ip 

 (Fig. 3) in front of the pleuron of the prothorax in the roach, 

 are called the lateral cervicals. 



The ventral intersegmentals are the prebasisternite Pbs 

 (Figs. 2, 3 and 5), the intersternites, Is (Figs. 2 and 3), and 

 possibly the spinasternite, S\y (Figs. 2, 3 and 5). The pre- 

 basisternum and intersternites, Pbs and Is (Fig. 3) in front 

 of the prosternum of the roach, earwig, etc., are termed the 

 ventral cervicals. All of these sternites appear to be parts of 

 the segment behind them. 



It is thus apparent that the cervical sclerites (cervicalia) are 

 in all probability homologous with the intersegmental sclerites 

 (intersegmentalia) in front of the other thoracic sclerites, and 

 these doubtless belong partly to the segment behind them, 

 partly to the segment in front. It is thus as incorrect to re- 

 gard the cervical sclerites as representing the entire labial seg- 

 ment, as it would be to regard the intersegmental sclerites in 

 front of the metathorax as representing the entire mesothoracic 

 segment; for these intersegmental (and cervical) sclerites be- 

 long partly to the segment behind them, partly to the segment 

 in front, as we have seen. 



The region containing the cervical sclerites is the veraccrvi.v, 

 or "cervicum." It would be simpler to designate this region as 

 the cervix, since it is the true neck region, but the term cervix 

 is always applied to the constricted occipital region of the head ; 

 on this account the "manufactured" term "cervicum," or the 

 compound term veracervix is preferable. The function of 

 the neck region is to enable the head to turn more readily. 



