in] FOSSORES OR DIGGER-WASPS 33 



the legs of such species as C. cribrarius and C. pel- 

 tariiis. In the male of the former the femora of the 

 front legs are each drawn out posteriorly into a large, 

 twisted and five-sided process, and carry between this 

 remarkable structure and the attachment to the body 

 a sharp prong ; while the corresponding part of the 

 front leg of the latter is adorned with a flat, polished, 

 yellow outgrowth which has at its base a very slender 

 spike. The front legs of the male of C. peltarius are 

 yet further singular in that the inner of the two 

 claws is flattened and spread out at its base into 

 a thin plate which is drawn out at its tip into a 

 narrow twisted spine. Curious modifications of more 

 or less similar form occur also in the legs of the 

 males of C. scutellatus, C. interrupting and C. elypeatm ; 

 but these need not be specified in detail. 



Enough has been said to call attention to these 

 peculiarities that occur with such frequency within 

 the limits of this one genus; and we trust that the 

 reader has begun to wonder, as we ourselves still do, 

 what purpose and function is served by these odd 

 and often ungainly developments and departures from 

 the ordinary type of structure. We regret that we 

 are entirely unable to give any information on these 

 points with regard to any one of the species con- 

 cerned. So far as we are aware no knowledge has 

 ever been obtained as to the use or uses of any of 

 these structures. It is difficult, to a believer in 



L. B. W. 3 



