1913.] NATURAL SCIENCES OF PHILADELPHIA. 405 



is divided into numerous natural groups everywhere in its distribution 

 as in North America. 



A number of species treated in the present paper are found in both 

 brachypterous and macropterous forms, while others are known from 

 brachypterous or macropterous individuals only. These facts have 

 been treated under the Biological Notes for each species, as habit 

 and environment appear to have been chiefly instrumental in such 

 development. These differences are almost wholly without value as 

 specific characters, and, since they have been frequently so used^ 

 have given rise to much confusion in the past literature. 



Subgenus ALLONEMOBIUS n. subgen. 



The subgenus includes four species and three geographic races 

 from North America. Type of Subgenus — Nemobius fasciatus 

 [Gryllus fasciatus] (De Geer) . 



Suhgeneric Description. — Size large to small for the genus. Disto- 

 ventral spurs of caudal tibia very unequal in length. Proximo- 

 internal spine of caudal tibia in male specialized as described under 

 Morphological Notes for the genus; other spines of caudal tibia 

 below concave, with margins of this sulcation minutely serrulate in 

 both sexes, the disto-internal spine not specialized. Ovipositor long 

 and nearly rigidly straight; apex with margin of portion formed by 

 dorsal valves obliquely subtruncate and armed with teeth, the 

 portion formed by ventral valves unarmed. 



Nemobius fasciatus (DeGeer). 



1773. Gryllus fasciatus De Geer, Mem. I'Hist. Ins., Ill, p. 522, PI. 43, fig. 5. 



(Original description.) [Pennsylvania.] 

 1775. A[cheta] hospes Fabricius, Syst. Ent., p. 281. (Description.) 



[America.] 

 1791. Gryllus hospes Olivier, Encycl. Meth., VI, p. 636. (First use of name.) 

 1835. Acheta servilis Harris, Hitch., Kept. Geol. Mass., 2d ed., p. 576. 



[Massachusetts.] 

 1841. Acheta vittata Harris, Ins. Inj. Veget., 1st ed., p. 123. (Description.) 



"1847. ^^ Acheta vittata Fitch, Am. Jour. Agr. Sci., VI, p. 146. [New York.]" 

 18.54. Acheta vittata Jaeger, No. Am. Ins., 1st ed., p. 160. [Brief notes on 

 habits.] 



1861. Nemobius viltatus Packard, Rept. Nat. Hist. Me., 1861, p. 376. 

 [Chamberlain Farm, Maine.] 



1862. N[emobius] exiguus Scudder (not Acheta exigua Say, 1825), Bost. Jour. 

 Nat. Hist., VII, pp. 429, 430. [St. Louis, Missouri; Minnesota.] 



1862. N[emobius] vittatus Scudder, Bost. Jour. Nat. Hist., VII, p. 430. 



[Massachusetts; Maine; Connecticut.] 

 1862. N[emobius] fasciatus Scudder, Bost. Jour. Nat. Hist., VII, pp. 430, 431. 



(In part.) [Massachusetts; Delphi, Indiana.] 



^ A reference in quotation marks indicates in the present paper that the 

 author has been unable to see that paper, otherwise all of the references have 

 been verified. 



