REHN AND HEBARD 43 



groups of the same. The New England States form part of 

 the range of three species, the Middle Atlantic States and the 

 mountainous region of the southern states of four species, while 

 but two species are found in the northern Mississippi Valley 

 and but one reaches Arkansas. The genus is thus seen to be a 

 group of essentially austral character. 



Of the species of Group A, testaceus is a more northern adap- 

 tation of the austral pachymeriis type, while davisi is the more 

 nearly boreal of any of the forms of the genus, being represented 

 in the southern Appalachians by the allied monticola. The 

 single species of Group B (americanus) occupies an area in gen- 

 eral more or less elevated and somewhat to the northward of 

 the range of the single species of Group G (gibbosus), which latter 

 extends southward to central Florida. Of Group D all are 

 Coastal Plain or Floridian, dorsaUs is coastal and north Floridian, 

 occurring with calcaratus, which latter is also north Floridian 

 and Coastal, replaced in central and south Florida by glaber. 



History. — In 1838, Burmeister ^ described two species of this 

 genus from South Carolina, calling them Decticus pachymerus 

 and dorsalis. In 1859, Saussure'* described a new genus and 

 species from Tennessee, as Orchesticus americanus, this clearly 

 being a member of the present genus. The generic name Orches- 

 ticus has been generally used for a quite different genus. Scud- 

 der, in 1862,^ used the Burmeisterian names for two species found 

 in the northeastern states, which he referred to the Old World 

 genus Thyreonotus. In 1869, Walker ^ described a species from 

 Massachusetts as Decticus derogatus. Brunner, in 1893,'' de- 

 scribed a genus Engoniaspis in a key, basing it on an undescribed 

 species from Missouri. A sketch of this species, later supplied 

 to Caudell,^ showed it to be a member of the present genus. 

 In 1894, Scudder ^ published a brief key to the species of the 

 genus, which he there diagnosed and named Atlanticus, also 



3 Handb. der Entom., ii, abth. ii, pt. 1, pp. 712 to 713, (1838). 

 * Revue et Magasin de Zoologie, 2e ser., xi, p. 201, (1859). 

 8 Boston Journ. Nat. Hist., vii, p. 453, (1862). 

 ^Catal. Dermapt. Saltat. Brit. Mus., ii, p. 260, (1869). 

 ' Ann. Mus. Civ. Stor. Nat. Geneva, xxxiii, p. 185, (1893). 

 sProc. U. S. Nat. Mus., xxxii, p. 325, fig. 29, (1907). 

 ^Canad. Entom., x.w-i, p. 180, (1894). 



TRANS. AM. EXT. SOC, XLH. 



