APPENDIX. 313 



tennse to the occiput and together with an insulated spot 

 each side on the vertex when viewed from behind pre- 

 senting the form of the figure 3, white ; a white slightly- 

 oblique spot above the base of each antenna ; inferior 

 orbits white ; thorax with an abbreviated, transverse, 

 angulated line before, slightly interrupted in the middle, 

 a line before each wing and three small spots on the mid- 

 dle placed triangularly, white; ivings hyaline, nervures 

 i\xsco\xs;feet yellowish-white; abdomen rufous, first seg- 

 ment, and sometimes the tip, black. 



Length from more than three-tenths to two-fifths of an 

 inch. 



CEPHUS, Latr. 



1. C trimaculatus. Black ; abdomen with a yellowish- 

 white spot each side at the middle. 



Inhabits Pennsylvania. 



Orbits before, two longitudinal spots on the hypostoma, 

 and base of the mandibles yellowish-white ; wings brown- 

 black ; metathorax with a pale greenish, membranaceous, 

 triangular spot behind ; abdomen on the middle with a 

 transverse oval pale yellowish spot each side. 



Length % nearly one-half, 9 nearly three-fourths of an 

 inch. 



Var. a. head immaculate. 



Var. /3. a very small indistinct spot each side beyond the 

 middle. 



In the collection of Mr. William W. Wood, the great 

 difference in point of size between the sexes of this insect, 

 might readily lead to error with respect to their specific 

 identity. 



3. C. abbreviatus. Black ; abdomen rufous at base. 



