406 FAMILY VI. ACRIDIDJE. THE LOCUSTS. 



domen, their tips narrowly rounded; in typical form reaching, female, or 

 slightly surpassing, male, the tips of hind femora, the latter surpassing the 

 abdomen 5 mm., male, reaching its tip or slightly beyond, female. Supra- 

 anal plate broadly triangular, nearly flat, its tip obtuse; median sulcus 

 percurrent or nearly so, expanded at apical fifth. Cerci short, very broad, 

 the apical half bent upward and widened ventrally to form an obliquely 

 transverse oval lobe, much wider than the base; its apex broadly and ob- 

 liquely rounded, the dorsal angle more produced and more narrowly 

 rounded than the ventral one. Subgenital plate as described in key. 

 Length of body, $ , 25 29, $, 2734; of antennae, $, 13.515, $, 1214; 

 of pronotum, $, 6.57, $, 78.2; of tegmina, $, 11.513, $, 912; of 

 hind femora, $ , 16 18, $ , 17 21 mm. Length of tegmiua, long-winged 

 form, $ , 21, $ , 24 mm. 



This large bulky species varies greatly in wing-length, but only 

 the short-winged form, the Pczotettix viola of Thomas (1876, 68) 

 is known from east of the Mississippi, having been recorded from 

 Illinois, Kentucky and Hattiesburg, Miss. The types of Thomas 

 were from central and southern Illinois, while those of the long- 

 winged form, typical ponderosiis, were from Dallas, Texas. Scud- 

 der, in his key (1897, 138) separates the two forms only by the 

 comparative length of tegmina and color of hind tibiae. Cotypes 

 (labelled "types") of pondcfosus ("robustus") from Dallas, re- 

 ceived from him are at hand, as well as undoubted specimens of 

 viola from Fayetteville and Cane Hill, Ark., and are almost exact- 

 ly alike except in length of tegmina and color of hind tibise, the 

 apical two-thirds of the latter in ponderosus being "yellow tinged 

 with red," instead of distinctly red as in the Arkansas short- 

 winged form. The male cerci and other abdominal organs are 

 the same, with the exception of the median sulcus of supra-anal 

 plate which in robust us is interrupted or closed for a short dis- 

 tance at apical third. Morse (1907, 51) records robustus from 

 numerous points in Arkansas, Oklahoma and Texas, stating that 

 it "is a characteristic inhabitant of woodlands, usually xerophytic, 

 where it hops about among the underbrush with vigorous leaps." 

 He states that "it is very variable in wing-length but not dimor- 

 phic, the tegmina of the male ranging from 12 to 24 and female 

 from 13 to 24 mm. ; and also in the color of the hind tibise, the dis- 

 tal two-fifths of which range from pale yellow to bright coral red." 

 He doubtless had both forms before him but did not recognize the 

 shorter winged ones as the riolit of Thomas, though he had pre- 

 viously (1907, 50) taken M. rlola at Hattiesburg, Miss. 



Garman (1894) has recorded the short-winged form from sev- 

 eral points in central and western Kentucky, stating that it is 

 "moderately common on low land along streams and increases in 



