THE ENTOMOLOGIST. ;3 



them, but the female is also to be known by the broad lanceo- 

 late form of the apical anal segment, which is terminated by 

 a narrower point, as shown in figure 11; 10 represents, in 

 profile, the apical segmeiits of the same sex ; 13 is the apical 

 segment of the male, viewed as above j and 12 is the profile 

 of the same. 



2. C. simplex. The female of this species is readily dis- 

 tinguished by its more elongate and narrower ventral seg- 

 ment ; the abdomen is also proportionably longer than in C. 

 quadridentata ; in small examples the ventral plate tapers to 

 a point, with scarcely any indication of the notch at the sides 

 near the apex, being simply lanceolate ; the normal form of 

 the valve is shown in figure 6 ; the profile of the apical seg- 

 ment, showing the inferior plate to be much longer than the 

 upper, is seen in figure 5, 



The male may be distinguished by viewing the abdomen 

 above, when the two upper spines at the apex will be seen 

 to be directed outwardly, as shown in figure 7 : these spines, 

 in C. rufescens and in C. umbrina, are straight and parallel. 

 At the lateral basal angles of the segment a minute spine will 

 be observed very visibly projecting : this spine will also be 

 found in the other species, but usually it is very minute, and 

 never so prominent as in the male of C. simplex : figure 8 is 

 the same segment in profile. 



3, C. rufescens is very like C. umbrina, but is certainly 

 a very distinct species j in both, the plates of the apical 



