72 Journal New York Entomological Society. tVoi. xxiv, 



and bead-like, while the abnormal development of the head cauues 

 them to be unusually widely separated. 



Very decided size variation frequently occurs, this is not geo- 

 graphic, though in series from the same general region, those from 

 high elevations show shorter and heavier limbs to varying degrees. 

 Certain individuals appear to be fully adult, but if so are astonish- 

 ingly small. Other immature specimens, with genitalia showing them 

 to be in early instars, are surprisingly large. It is evident from the 

 series before us, that almost every instar may be found at the same 

 time in the same locality. Until careful breeding experiments are 

 made it will be impossible to determine exactly the life cycle of these 

 singular insects,^ to explain the great disparity in size frequently 

 found in apparently the same instar and to distinguish readily the 

 adult condition. 



As to the Mexican species, we may state from examination of 

 small series, that a number are extremely distinctive ; that probably 

 the most widely distributed of the species, ^. talpa, should withouc 

 doubt have a number of synonyms, and that, though the majority of 

 the more northern species are certainly distributed southward beyond 

 the Mexican boundary, none of the more southern species reach 

 northward as far as that line.- 



Stenopelmatus Burmeister. 



1838. StenopeUnatiis Burmeister, Handb. der Entom., II, abth. II, pt. I, p. 720. 

 The genus was based on five species. Genotype: St^cnopelmatiis'] 

 talpa Burmeister, selected by Kirby. 1906.^ 



Key to the Species of the Genus Stenopelmatus Found in the 

 United States. 



(Vertex without carinae. Head and pronotum not decidedly punctate. 

 Tegmina and wings absent. Caudal limbs with tarsi much shorter than tibia;. 

 General coloration never black.*) 



1 The great preponderance of immature material in the collections before 

 us suggests the possibility that more than a year is required in the transition 

 from the egg to the adult condition. 



2 Records of S. his trio from the United States by Scudder and Fchn are 

 all misidentifications, applying rightly to S. fusciis and 5". longispiiia. 



3 Synon. Cat. Orth., II, p. in. 



■t These features variously occur in certain Mexican species : some of 

 them probably showing sufficient differentiation to warrant generic separation. 



