NO. 1124. RE VISION OF THE MELA NOPLISC UDDER. 399 



wanting; metazoua less than half as long a& the prozona, the latter 

 divided a little behind the middle by a scarcely perceptible sinuate 

 sulcus; lateral lobes nearly twice as long as broad, narrowing down- 

 ward, the inferior margin very broadly angulate, the posterior margin 

 roundly excised. Prosternal spine blunt, conico-cylindrical ; inner mar- 

 gin of mesosternal lobes broadly convex, the lobes subapproximate 

 (male) or distant from each other by half their width (female); meta- 

 sternal lobes subcontiguous in both sexes. Tegmiua linear, about as 

 long as the pronotum, or absent. Hind femora extending nearly to 

 (female) or a little beyond (male) the tip of the abdomen, the superior 

 margin unarmed, the hind tibiae with their outer edges smooth, the 

 spines similar in length on the two sides, those of the outer series nine 

 to ten in number; first and third tarsal joints equal, the second less than 

 half as long as either. Abdomen indistinctly carinate throughout, the 

 extremity scarcely enlarged in the male; subgenital plate ampliate at 

 base, short, not projecting far beyond the tip of the small supraanal 

 plate, and in particular so little elevated posteriorly as to expose the 

 recumbent pallium more or less to a posterior view; furcula feeble; 

 cerci styliform; infracercal plates highly developed. 



In general appearance the species of this genus most nearly resemble 

 those of Gymnoscirtetes Bruner, Paradichroplus Brunner, and Scopas 

 Oiglio Tos. The distinctions of the genus from the first, besides its 

 ampliate subgenital plate, are pointed out under that genus. From 

 Paradichroplus it differs in its more compressed body, the more taper- 

 ing vertex, the slenderer tegmina (when they are present), the lack of 

 any enlargement of the tip of the male abdomen, with the shorter sub- 

 genital plate, the ampliate basal margin of the same, the posteriorly 

 exposed pallium, and the wholly simple cerci. From Scopas, which I 

 have not seen, it appears to differ in its more prominent prosternal 

 spine, its narrower labruin, more declivent face, less cylindrical pro- 

 notum, with its excised posterior margin, besides its simple cerci. Its 

 subconical head, especially in the female, gives it a peculiar aspect. 



A. sphenarioides Scudder, is the type. 



Three species occur in the Southern States along the borders of the 

 Gulf of Mexico, and may be separated as follows: 



ANALYTICAL KEY TO THE SPECIES OF APTENOPEDES. 



A 1 . Tegmiua present in one or both sexes ; frontal costa no broader at base than in 

 the middle. 



6 1 . Tegmina present in both sexes; furcula of male as long as the last dorsal seg- 

 ment; anal cerci tapering only on basal half 1. sphenarioides (p. 400). 



6 2 . Tegmina present in female only; furcnla of male not more than half as long 

 as the last dorsal segment; anal cerci tapering almost uniformly through- 

 out 2. rufovittata (p. 401). 



A 2 . Tegmiua present in neither sex; frontal costa much broader at base than in 

 middle, at least in the male 3. aptera (p. 402). 



