ART. 9 DIGGER WASPS OF GENUS PODALONIA FERNALD 37 



This very widely distributed insect has been perhaps the greatest 

 sufferer in the genus, from the belief of the older workers on Sphecids, 

 both in this country and in Europe, that color area was a reliable 

 means of distinguishing species. The result was that a specimen with 

 two ferruginous abdominal segments was considered different from 

 one having three, four, or more of that color. Variation in the color 

 of the hairs and the place where they ceased to be white and became 

 black has also caused trouble, and other varying characters have also 

 contributed to the confusion. 



For more than three years I labored to find some reliable separa- 

 tion of the species here listed as synonyms of molacei'pennis , studying 

 long series of specimens again and again, and even making mounts of 

 the genitalia and last ventral abdominal plate, but without success. 

 Finally I arranged the material geographically and at once order 

 began to come out of chaos, a series of beautiful gradations develop- 

 ing, closely paralleled by humidity conditions in different regions. 

 A similar stud}^ in the genus Sphex^^ gave exactly similar results, and, 

 in the same way, the various species listed under the bibliography of 

 violaceipennis all fell into line. 



Abnormal venation in this species is sometimes met with. In one 

 specimen seen the left fore wing has the second transverse cubital 

 vein forked in its anterior half, forming an extra, triangular cell 

 against the radial cell, and in that region separating the second and 

 third cubital cells. The fore wing of the other -side is normal. More 

 or less barrel shaped third cubital cells are sometimes met with, and 

 various other abnormalities occasionally occur. 



SPECIES OF UNCERTAIN POSITION 



PODALONIA JASON (Cameron) 



Ammophilajason Cameron, Biol. Centr.-Amer., Hym., vol. 2, p. 20, 1888. Female. 



A study of Cameron's type gives the following facts: Clypeal mar- 

 gin rounded, with four slight, rounded projections located about 

 where the teeth are in valida but not like teeth. Possibly the teeth 

 might wear down to this condition. Antennal scape shining, almost 

 piceous; third antennal segment one-third longer than the fourth 

 (not "more than twice the length of the fourth" as Cameron writes). 

 The wings are more fuliginous than in average specimens of valida 

 but this specimen is from Guatemala and quadridentata is an evidence 

 how a related form from the South is dark; the markings on the pro- 

 podeal shield differ somewhat from those in typical valida but are 

 well within the limits of variation of this part; the legs are not seri- 

 ceous but this is liable to wear off in old specimens and the clypeal 

 teeth suggest that. this may have been the case. 



11 See Ann. Ent. Soc. Amer., vol. 19, p. 88, 1926. 



