12 PROCEEDINGS OF THE NATIONAL. MUSEUM vol.71 



connection with this name; that in this description reference is made 

 to another species known to be a Psammophila; that the structure of 

 the petiole is that of Psammophila; and that the only reason for 

 another generic name is the petiolated second cubital cell. Thus a 

 name proposed only as an illustration of the ease with which a sig- 

 nificant generic name could be formed becomes actually available as 

 a substitute for Psammophila. Its standing is that of a monobasic 

 genus, its generic characters to be found among the specific charac- 

 ters given for its genotype, hocandei, and its relation to one other 

 species indicated. 



It seems one of the ironies of fate that a name suggested under 

 such circumstances as these and most emphatically rejected by its 

 author, being used only as an illustration, should obtain an accepted 

 standing. Yet no other name, except the unavailable Psammophila 

 has been given to these insects. Thus it seems necessary to violate 

 the evident desire of Spinola and estabUsh Podalonia as a genus in 

 full standing. The whole situation, as regards Spinola, at once brings 

 to mind the case of Ignotus aenigmaticus Slosson (Coleoptera). 



GENERIC CHARACTERS 



Podalonia, as here considered, may be distinguished most readily 

 from Sphex, in most cases, by the petiole. In Sphex this slender por- 

 tion involves two segments, the second being larger, though shorter, 

 than the first, and increasing only slightly backward in size. In Poda- 

 lonia we find only one segment in the petiole, the dorsal plate of 

 this segment (here counted as the first abdominal dorsal plate) being 

 quite large and increasing rapidly in size backward. There are some 

 species, however, in which this plate is rather intermediate between the 

 two conditions and these specimens are liable to be perplexing, and in 

 such cases other characters need consideration. In Podalonia the 

 comb teeth on the longer hind tibial spine are not crowded as closely 

 together as in Sphex and are coarser, and the spiracle on the first 

 abdominal dorsal plate is in front of, or at least not behind, the middle 

 of the length of the plate. 



If these characters were absolutely fixed, no difficulty in separating 

 Podalonia and Sphex would be encountered, but in a few cases the 

 spiracle is found slightly behind the middle of the plate in Podalonia 

 and there are degrees of crowding and in the coarseness of the comb 

 teeth which, in individual specimens, may make the determination of 

 the genus difficult in those cases, and final placing of the insect must 

 be made according to the evidence from all three characters. 



Where pubescence is present in the female (except in P. nicholi) 

 the insect may safely be considered a Sphex. In the male, pubescence 

 on the clypeus is useless as a distinction, but it does not seem to occur 

 elsewhere on the body (exceptions?) . A series of parallel rugosities 

 on the side of the pronotum in front of the prothoracic lobe, running 



