124 AMERICAN HYMENOPTERA. 



mens of cayenyiensis are still extant and, without his type, it 

 is absolutely impossible to tell whether he had incarum or 

 this species. His specimen came from Cayenne. I have not 

 seen Cresson's type of medius. It is probably in the collec- 

 tion of the United States National Museum. I have, how- 

 ever, seen specimens labelled ''''medius'''' by Cresson, in the 

 collection of the American Entomological Society, and those 

 specimens were specimens of this species. The type locality 

 (Utah), given for viedius by Cresson, is certainly incorrect. 

 Among all the specimens, which I have seen from the west- 

 ern United States, there was not one which could have be- 

 longed to this species, and Prof. Cockerell states (Psyche, 

 XII) that this species is not present in the western States, 

 but is Mexican. Col. C. T. Bingham failed to locate Smith's 

 type specimens of unifasciatus in the collection of the British 

 Museum for me, and it is impossible to tell from Smith's de- 

 scription whether his specimens belonged to viedhis or mexi- 

 canus. They came from Guatemala (at 5,000 feet altitude), 

 Costa Rica (Irazu at 6,000-7,000 feet altitude) and "San 

 Francisco " at 4,500 feet altitude. 



Pile rather short and coarse atid considerably variable in coloration 

 The typical form has the dorsum of the thorax yellow, zvith a broad 

 black itiieralar band, and the third dorsal abdominal se,i(ment yellow, 

 but is otherwise entirely dark in the females and also mostly so i7i 

 the males, except for some light pile on the face and sotne ferruginous 

 pile on the very apex of the abdometi. This typical form grades com- 

 pletely i?ito a fortn which, aside from the third dorsal abdominal seg- 

 ment, is entirely black in the fetnale caste and also mostly black iti the 

 male, except for the ferruginous pile on the hypopygiuni and epipygium. 

 Abdomen of fetnale rarely entirely black. 3Ialar space of females shorter 

 than its width at apex, a little more than one-fifth as long as eye. Geni- 

 talia with outer lobe of squaince well developed and rather pointed at tip. 



Queen. Head. — Entirely dark. Malar space distinctly shorter than 

 its width at apex, a little more than one-fifth as long as eye. Clypeus 

 moderately punctate, with mostly rather coarse punctures, the front 

 part of the disc, however, with the punctures sparse. Third antennal 

 segment longer than fifth, the fifth longer than the fourth. 



Thorax. — Dorsum yellow in front and on scutellum, with a very 

 broad black band between bases of wings (this band is distinctly more 

 than half as wide, from front margin to rear margin, as it is long, 

 from wing base towing base). Yellow pile extending down, from 



