172 connecticut geol. and nat. hist. survey. [bull. 



Tremecinje. 

 Tremex Jurine. 

 *T. columba Linnaeus. Howard, Insect Book, p. 70, Fig. 

 41 ; PI. xii, Figs. 27 and 23 ; PI. xiii, Fig. 31. 



Body varying from almost entirely black with yellow trian- 

 gular marks on the abdomen, to almost yellow with a narrow api- 

 cal black margin ; antennae usually yellow ; legs usually pale, 

 femora black above in dark individuals; wings varying from 

 strongly infuscated to yellowish hyaline. Length 18-40 mm. 

 Larva bores in maple, elm, apple, pear, beech, oak, and sycamore. 

 Connecticut (E. N).; New Haven (Bolton) ; East Hartford 

 (W. E. B.). 



cephim:. 



Key to Genera. 



1. Radial cross-vein always shorter than first abscissa of radial 



sector, the two converging toward the radio-medial cross- 

 vein 2 



Radial cross-vein subequal in length to or shorter than 

 first abscissa of radial sector, the two subparallel; base 

 of radial sector sometimes atrophied; posterior tibiae with 

 two preapical spurs Janus p. 172 



2. Posterior tibiae with one preapical spur 3 



Posterior tibiae with two preapical spurs 4 



3. Flagellum with first two or three segments usually distinctly 



contracted; posterior tarsal claws bifid . . . .Macrocephus p. 174 

 Flagellum never with first two or three segments distinctly 

 contracted, distinctly thicker in the middle than at base or 

 apex; posterior tarsal claws broadly expanded at apex 



and slightly emarginate between the two portions 



Adirus p. 173 



4. Abdomen of male with two apical ventral segments with 



fringes or brushes of bristles, sometimes placed in deep 

 scars; saw-guides of female, as seen from above, widened 



at apex -Trachelus p. 174 



Abdomen of male with ventral apical segments sometimes 

 with short hairs, never with fringes or brushes of bristles; 

 saw-guides of female, as seen from above, with their 

 sides parallel and not widened at apex Cephus p. 174 



Janus Stephens. 



Key to Species. 



I. Front wings with base of radial sector always present 2 



Front wings with base of radial sector always atrophied; 



