LONG S SECOND EXPEDITION. 239 



the basal band widely interrupted, second band less widely inter- 

 rupted, tbe penultimate one hardly interrupted, the ultimate one 

 entire. 



Length about seven-twentieths of an inch. 



That these three species are congeneric is evident, but they do 

 not correspond in all respects with the genus Megachile as de- 

 fined by entomologists. The tropin agree very well, and the 

 form of the nails of the feet in the two sexes are also similar, but 

 the tergum is convex, as in Oxmia, and the abdomen curves very 

 much downwards towards the tip, as in Stelis, from which latter 

 genus they differ by having a hairy venter. 



CAELIOXYS Latr. ' 



C. 8-DENTATA. — Black; abdomen with five white bands, tip 

 eight-toothed. 



Inhabits United States. 



% Front and hypostoma with dense, long, dull yellowish hair ; 

 thorax with a clentated band before, interrupted in the middle, a 

 spot at the base of the wings and a transverse line at base of the 

 scutel, white ; wings a little dusky on the apical margin ; feet 

 rufous; tergum with five white bands, of which the two or three 

 terminal ones are double; segments each with a transverse in- 

 dented line; tip with eight teeth, of which two are on each side, 

 and four at the extremity placed two above and two beneath ; 

 venter with a white line on the posterior margin of each segment, 

 the basal and terminal ones obsolete. [354] 



Length two-fifths of an inch. 



Var. a. Spots and lines of the thorax obsolete; feet excepting 

 the tarsi, black. 



This is an inhabitant of various parts of the United States, 

 from the North-west Territory to Arkansa, and is common in 

 Pennsylvania. 



NOMA DA Fabr. 



N. bisionata. — Terminal half of the wings with a dusky 

 margin; abdomen rufous, with a bright yellow spot each side of 

 the middle. 



Inhabits United States. 



9 Head ferruginous, front with a large, black spot, confluent 



