SUBFAMILY VII. RHAPHIDOPHOKIX.K. 615 



The genus CcutJiojtliiliis is one of the largest among the Tet- 

 tigoniid?p, and is confined to North America, and mostly to the 

 United States. Scudder (1804) revised it, reducing to synonyms 

 a number of those previously described, but describing so many 

 new forms that, in the end, he had 57 species, 24 of which were 

 ascribed to the eastern states. His key and descriptions were 

 based mainly on slight differences in the relative length of the 

 fore and middle femora and hind tibi;e; the spiuation of the hind 

 femora and other variable characters, so that the key is practi- 

 cally worthless. A number of his nominal species were based 

 upon nymphs, in some of which the structural characters differ 

 much from those of the adult. 



On account of the great number of forms, the absence of teg- 

 mina and Avings, the similarity of hue and general facies, the study 

 of this genus has been by far the most difficult part of this work, 

 and the results in the end are not on the whole satisfactory. 

 Scudder in his key did not take into consideration the characters 

 pertaining to the secondary genital organs, which I have mainly 

 used and which I have found far more stable than in most other 

 groups of Orthoptera. My studies have shown that the adult 

 males are quite readily separated by the variation in the form 

 of the snbgeuital and supra-anal plates and the last dorsal seg- 

 ment of abdomen, while the females can usually be distinguished 

 by the form and arrangement of the teeth on the inner valves of 

 the ovipositor. As the two sexes are colored alike and are 

 usually found in close proximity, the student who collects his own 

 specimens will find little difficulty in placing the females by the 

 key given below, which pertains mainly to the male sex. The color 

 characters vary so greatly according to age and environment that 

 except in J<itens, In-evipes, ulilcri and one or two others, they can- 

 not be used in a key, while the armature of the lower cariutp of 

 hind femora is constant only in iii</ricaitx, brcvi^cs and tcrrcstri*. 

 Many of the records in the local lists hitherto published are based 

 on wrong identifications and the known range of the various 

 species is, therefore, difficult to state. 74 



KEY TO EASTERN SPECIES OF CEUTHOPHILUS. 



a. Each inner valve of ovipositor with six or seven very short and api- 

 cally rounded teeth; ovipositor shorter than fore femora; male 

 unknown. 290. ENSIFER. 



aa. Each inner valve of ovipositor with four (rarely three or five) teeth 

 and a terminal hook, the tips of teeth acute (PI. VII, i s) except in 

 tenebrarum. 



T4 A11 the drawings for the original illustrations showing the structure of abdominal 

 appendages of Ceuthophilus were made by Dr. H. Fox. 



