198 



Annals Entomological Society of America [Vol. XV, 



of abdominal segments than usual in this order, elongate 

 body form, and long, many-jointed antennae, would seem to 

 justify the suggestion that this family may represent the 

 most primitive of modern beetles. If this is true, it seems 

 probable that the Coleoptera had its origin in a Lampyrid-like 

 ancestral form. 



On the other hand, the Carabidae exhibit a distinct and 

 rather a specialized type of venation which is characteristic 

 of a group of families, including the Gyrinidae, Dytiscidse, 



CAJJABWAE' 



ZT CARABIOAE 



ET GTRINIDAE 



IZm Gy^PIMlDAE 



IX HYPOTHETICAL TYP£ 



I. Cicindela vulgaris Say. 



II. Carabidae. 



III. Harpalus caligittosa Fab. 



IV. Carabidae. 



V. Carabidae. 



Fig. 4. 



VI. Anisodactylus discoideus Dej. 

 VII. Gyrinus analis Say. 

 VIII. Dineutes assimilis Aube. 

 IX. Hypothetical Coleopterous 

 Type. 



Cicindelidae, and probably others. (Fig. 4). This group is 

 characterized by the presence of cross veins r - m, by the per- 

 sistence of the fused part of R3-I-R4 which turns forward to 

 the margin of the wing, and by the fact that the transverse 

 fold cuts through branches R2+3 and R,4 leaving these veins 

 in the apical part of the wing. 



The Cerambycidae and Chrysomelidas typify another group 

 of families having similar venation. This type includes a large 



