REHN AND HEBARD 83 



showing a proportion to length of from 50 to 58 per cent in the 

 female. Of these figures the Billy's Island males alone show 

 from 51 to 58 per cent in the male and 53 to 58 per cent in 

 the female. The area of least width is as little correlated with 

 the relative caudal width proportion as in the other species, but 

 the general form of the disk is more uniform in this species than 

 in other forms. The lateral carinae of the pronotal disk vary 

 but slighth' in the degree of their indication. The cephahc 

 margin of the pronotal disk varies from subtruncatc to shallowly 

 arcuato-emarginate; the caudal margin is always greatly arcuate. 

 The lateral lobes of the pronotum have their greatest depth 

 contained t^vice or nearly twice in their greatest dorsal length, 

 while there is some variation in the truncation or arcuation of the 

 ventral margin of the same; the humeral sinus is slightly more 

 indicated in some specimens than in others, but in all it is weak 

 or subobsolete. The male tegmina reach, but generally do not 

 surpass, the caudal margin of the pronotal disk, in several spec- 

 imens they project slightly. The female tegmina are deeply 

 buried under the pronotum. The usual dorsal and lateral carinae 

 of the abdomen are at most but weakly indicated in this species, 

 generally being obsolete. The disto-dorsal abdominal segment 

 is angulato-emarginate mesad in both sexes; in the male the 

 angle varies from acute to rectangulate, in the female it is ro- 

 tundato-obtuse, the resultant lateral angles moderately sharp. 

 The supra-anal plate is acute in both sexes. Cerci of the male 

 uniform in their form and curvature. Subgenital plate of the 

 male always fissate-emarginate, styles moderately long and not 

 appreciably varying in length. Ovipositor always robust and 

 straight, the apex ventral, the length, as shown by the measure- 

 ments, varying from 21.2 to 29.2 mm. and not correlated with 

 that of the caudal femora. Subgenital plate of the female with 

 the median emargination moderately deep and narrow, almost 

 fissate, the lateral sections well rounded. Prosternal spines 

 always well developed and aciculate, occasionally very long; 

 mesosternal lobes varying from but shghtly more acute than 

 rectangulate to strongly acute-angulatc. The caudal femora 

 vary in length in a maimer largely correlated with general size; 

 the ventro-internal margins bears a scries of spines varying in 

 number from tw'o to nine. The median disto-internal spur of 



TRANS. AM. ENT. SOC, XLII. 



