158 STUDIES IN AMERICAN TETTIGONIIDAE (oRTHOPTERa) 



genus before us convinces us that the above characters are in- 

 sufficient. Moreover we are certain that the type species of 

 these subgenera, fasciatus and fuscus, possess no other differential 

 characters of sufficient importance to warrant the erection of 

 subgenera. The North American species which we place under 

 the subgenus Xiphidion are naturally separated into three groups, 

 but it would be necessary to erect countless subgenera for the 

 genus were these considered subgenerically distinct. The Old 

 World species having no teeth, or two, instead of the usual one on 

 each male cercus, are certainly more distinctive than these and 

 may constitute valid subgenera, while the variation, within the 

 genus, of the male subgenital plate affords even more decided 

 genital characters, being acutely produced distad without styles 

 in some, acutely produced distad with styles in others and not 

 produced but bearing styles in the majority of species. 



The very long ovipositor and very brief tegmina are used to 

 separate Thecoxiphidion from Xiphidion. The variation in the 

 ovipositor, not only in the type of this subgenus but in the majority 

 of the species which we havestudied, convinces us that this charac- 

 ter is insufficient for subgeneric use, and the tegminal length is 

 not to be considered of even specific value, as the genotype 

 itself, normally decidedly brachypterous, develops a macrop- 

 terous form. 



Key to the Subgenera of the Genus Conocephalus 



A. Prosternum bispinose. (Caudal tibiae armed at distal extremity with 

 three pairs of spurs.) 



B. Ventral margins of cephalic and median tibiae armed with five to seven i" 

 well spaced spines. 



C. Male subgenital plate very strongly produced meso-distad in two 

 sharp straight spikes, styles absent. 



Dicellura new subgenus 



CC. Male subgenital plate with distal margin more or less decidedly 



truncate, with no decided emargination or production; small, slender, 



filiform styles present laterad. Xiphidion Serville 



BB. Ventral margins of cephalic and median tibiae armed with nine to ten 



closely set spines. Palotta F. \\'alker 



AA. Prosternum unarmed. (Ventral margins of cephalic and median tibiae 



armed with five to seven '" well spaced spines.) 



'" In all of the North American species of the genus, the cephalic and median 

 tibiae have both ventro-cephahc and ventro-caudal margins armed uniformly 

 with six well spaced spines. 



