1906.] NATURAL SCIENCES OF PHILADELPHIA. 41 



the former is the type, the latter having been removed to Plectro- 

 phorus {=Plectrotettix) by McNeill. 



1895. Pseudostauronohis Giglio-Tos, Zool. Jahrb., Abth. Syst., VIII, p. 



808. Type.— P. brunneri Giglio-Tos. 

 1897. Plectrophorus McNeill, Proc. Davenp. Acad. Nat. Sci., VI, p. 198, 



251, pi. 4, fig. 21 [not of Ferussac, 1819]. Included Stenobothrus viatorius 



and gregarms Saussure. 

 1897. Plectrotettix ]\IcNeill, Psyche, VIII, p. 71. 



Of the various species here considered a series of one hundred and 

 fifty-six specimens have been examined, including typical material 

 of the five species described by Bruner. Thorough consideration of 

 this material shows that no tangible characters exist for separating 

 Scyllina, Pseudostauronotus and Plectrotettix even as subgenera as 

 proposed by Bruner.^^ The characters on which the subdivisions 

 were there made are: the presence or absence of an intercalary vein in 

 the post-radial area, the cells of this region being accordingly arranged 

 in two series or else irregularly reticulate; the caudal lobe of the 

 pronotum either subequal to or longer than the cephalic; the inner 

 claw of the hind tibiae more or not more than twice the length of the 

 outer, and the number of spines on the outer margin of the hind tibise 

 (9 to 12 or 1.3 to 16). 



The first of these characters can usually be depended upon as stable, 

 but in this genus the intercalary vein is by no means a stable character 

 being present or absent in individuals of the same species, and in some 

 cases varying in an individual to the extent that it is distinct on one 

 tegmen and absent on the other. The proportions of the lobes of the 

 pronotum are also found to vary, as in species belonging unquestion- 

 ably to the section supposed to have subequal divisions the caudal 

 section distinctly exceeds the cephalic in length, while the reverse is 

 the case in other species. The length and shape of the tibial claws 

 while diagnostic when the type species alone are compared, is without 

 value when other forms are considered ; specimens of varipes, which 

 is allied to conspersa, has the spurs no longer than is found in Mexican 

 forms referred to Plectrotettix. The number of tibial spines is a char- 

 acter which appears unworthy of use in separating subgenera, especially 

 when the extent of variation is such as to cause great doubt as to which 

 division a particular specimen belongs. 



Wliile the type of the genus Gomphocerus {Epacromia) peragrans 

 Stal,^^ has not been recognized since the original description, a cir- 

 cumstance probably due to the fact that the type locality is an unfre- 



^^Biol. Cent. Amer., Orth., II, pp. 99-100. 



^' Kongliga Svenska Fregatten Eugenies Resa, Zool., I, p. 343, 1860. [Puna. 



