348 STUDIES IN THE ISCHNOPTERITES (oRTHOPTERa) 



and less thickly so mesad. Subgenital plate strongly asymmetrical, convex 

 except at production where it is very weakly concave; dextral free margin 

 weakly convex to moderate mesal production, with which it forms a rounded 

 obtuse-angulation, margin of production roughly convex, bearing at its blunt 

 apex a heavy cylindrical style, directed evenly sinistrad, about three times 

 as long as broad, with bluntly rounded apex slightly deflexed sinistrad and with 

 dorsal and distal surface supplied with stout but minute teeth: sinistrad the 

 free margin from the apex of the plate's production is evenly and weakly 

 concave, with sinistral style, situated at base of production and less than half 

 as long as dextral style, small and weakly tapering to rounded apex. 



Characters of 9 . — (Bartica, British Guiana.) Similar to male in ambisexual 

 characters. Size slightly larger, form appreciably broader with pronotum 

 more ample. Head with interocular space slightly wider than interocellar 

 space. Tegmina and wings proportionately somewhat less elongate than in 

 male, scantily surpassing the cereal extremities. Supra-anal plate triangularly 

 produced, with apex broadly rounded, showing a broad and weak concavity 

 at the cereal bases.^^ Subgenital plate convex, very broad and weakly pro- 

 duced, with free margin evenly and very broadly convex. '^ 



Measurements (in millimeters) 



o*i •^■(f 05 



o V 



II |2 ^2 g!f ^^ 



C^ ^ ^^ ■^'^ ^" '^^ 



Montego Bay, Jamaica 13.8 3.8 4.8 14.6 4.3 



Sanchez, San Domingo 14,1 3.9 5 15.7 4.4 



Arecibo, Porto Rico 14 3.8 5.1 14.8 4.3 



Roseau, Dominica 13.5 3.7 4.8 15.1 — 



Old Panama, Panama 15 3.8 4.8 15.7 4.4 



9 



Montego Bay, Jamaica 15.6 4 5.1 14.7 4.3 



Ensenada, Porto Rico 14.5 4.6 5.7 16.8 4.7 



St. Croix, Danish West Indies 15.2 3.9 5 14.1 — 



Bartica, British Guiana 16 4.1 5.7i« 15.4 4.6 



Decidedly greater variation appears to occur in the present 

 species in very mountainous regions (see measurements of rufa 

 dehilis and rufa occidentalis) . 



The variation in the present race is apparently slight; the 



" This plate shows decided variation, being sometimes distinctly angulato- 

 emarginate distad, or with apex acute and .sharply rounded, while the lateral 

 margins are sometimes quite decidedly concave at the cereal bases, and some- 

 times with no emargination there. Such differences led Saussure and Zehntner 

 to consider that the triangular type repnvsented a distinct species, resulting 

 in the synonym conformis. 



1* Often, in the series before us, truncate, straight transverse, mcvsad. 



'" The pronotum of this specimen has been somewhat flattened out in being 

 l)repared. 



