MORGAN HEBARD 211 



Whereas aptera divides naturally into five geographic races, 37 

 showing as a rule decided uniformity in these races where they 

 occur, sphenarioides has apparently reached a less advanced 

 stage in its development. Subject to even greater geographic 

 differentiation, the recognition of not more than three races 

 appears to be advisable; a northern, a central peninsular and a 

 southern peninsular. Each of these is subject to decided differ- 

 entiation, in more than one case fixed over a portion of its range. 

 Thus the northern race can be separated readily into a western 

 and an eastern type, while a change from the eastern again 

 occurs to the south. Difference in a single feature in some cases 

 and sometimes marked instability leads me to believe that only 

 the three races mentioned above should be recognized and that 

 the other conditions should be treated as atypic of these, indi- 

 cating in some cases formative geographic races which are as 

 yet insufficiently differentiated to warrant nominal recognition. 



Nowhere in the Orthoptera have I encountered a species so 

 clearly divided into geographic races showing in themselves 

 from strong to weak evidence of further racial evolution. 



In sphenarioides a much more complicated subgenital plate is 

 developed than in any other species of Aptenopedes. In it the 

 subgenital plate forms only a comparatively narrow distal rim 

 of the very large proximal portion of the eighth sternite; this 

 shows upon external examination to have a nearly vertical sulcus 

 close to the proximal margin which converges to meet that 

 margin dorsad. When the subgenital plate is deflexed this sulcus 

 as well as the proximal margin are found to expand dorsad and 

 have there an intricately attached area of soft tissue which is 

 produced in a very large fleshy flap. When in normal position 

 this flap covers the side and caudal portions of the bulbous base 

 of the penis, but becomes erect and then assumes a latero- 

 external position when the penis is extruded. In addition the 

 internal margin of the subgenital plate bears a broad median 

 triangular integument which protects the base of the penis from 

 the rear but springs into an erect position when that organ is 

 extruded. 



37 With indices that in certain areas other races may be present but 

 should not be described without more adequate evidence, obtainable only 

 from more and larger series than are now available. 



TRANS. AM. ENT. SOC, LXII. 



