REHN AND HEBARD 169 



duction. As a result, in determining material with the present 

 paper, we would advise the use primarily of the keys, tables and 

 figures; the specific treatment of known species being here 

 employed mainh'^ to set forth the variation in each species and 

 its distribution. 



Subgenus Dicellura '■* new subgenus 



The subgenus includes a single species, from the Appalachian 

 region of the southeastern United States. 



Type of Subgenus. — Conocephalus allardi [Xiphidion allardi] 

 (Caudell). 



Suhgeneric Description. — Prosternum bispinosc. Subgenital 

 plate of male very strongly produced meso-distad in two sharp 

 straight spikes which are weakly divergent, styles absent; be- 

 tween the productions the distal margin of the plate is obtuse- 

 angulate emarginate at an angle of slightly over ninetj^ degrees. 

 Ventral margins of cephalic and median femora armed with six 

 well spaced spines. Caudal tibiae armed at distal extremities 

 with three pairs of spurs. Size medium for the genus, form ro- 

 bust. 



Conocephalus allardi (Caudell) (Pis. XV-XVII, fifj. 1: XVIII. 1 and 2; 



XIX, 9; XX, 1.1 

 1910. Xiphidion allardi Caudell, ^^ Ent. News, xxi, p. 58. [Tray and Blue 



^Mountains, Towns County, Georgia.] 



The present insect is widely separated from any other known 

 species of the genus by the characters given in the subgeneric 

 description. The species bears a slight superficial resemblance 

 to C. brevipennis but differs greatly in the characters mentioned 

 above, in the very broad tegmina of which the male tympanum 

 is unusually large for the species of the genus, and in the ovipositor 

 which is rigidly straight and exceeds in length the maxinmm 

 found in brevipennis. The anomalous male subgenital plate l^i'ings 

 to mind that of the South American species, C. vitticoUis and C. 

 longipes, but this plate is found upon examination to be an en- 

 tirely different development in the present insect. 



"From 6keXXa = fork and oiipd=tail, in allusion to the exceptional form of 

 the male subgenital i)late. 



15 Single type designated by Caudell and Heliard, Proc. Acad. Nat. Sci. Phila., 

 1912, p. 164, (1912). 



TRANS. AM. ENT. SOC, XLI. 



