1896.] NATURAL SCIENCES OF PHILADELPHIA. 63 



they are divergent. Wings as in larrece, but the marginal cell 

 rather more produced beyond stigma. A keel between antennae, 

 giving place to a groove running upward to middle ocellus. Color 

 deep orange, with dark markings. A black spot before the upper 

 part of each anterior orbital margin ; a large green-metallic patch 

 on vertex, enclosing the two posterior ocelli, but just escaping the 

 anterior one or only partly enclosing it ; mesothorax shiny metallic 

 olive-green, except rather broad yellow lateral margins ; dorsum of 

 metathorax dark green ; a large round dark patch on sides of thorax 

 beneath. Abdomen above more or less suffused with brown, which 

 is dark at base of first and apex of second segments, and becomes 

 reddish on last two segments. Hind legs tinged with brown. 

 Mandibles simple as in larrecB. 



Hah. — San Marcial, N. j\I., on Larrea at the same time and place 

 as P. larrece. One specimen. 



17. Perdita larrearum n. sp. 



9 . — 4 mm. long. Head dark brassy-green, thorax black, pleura 

 and metathorax bluish, abdomen dark sepia-brown. Head rounded, 

 rather large, vertex conspicuously roughened, cheeks and occiput 

 with a rather dense fringe of white hairs, clypeus and sides of face 

 very narrowly pale yellowish-ferruginous, the pale color continuing 

 along orbital margin some distance above level of antennae, but so 

 thin that its termination is difRult to trace. 



Antennae blackish above, yellowish beneath. 



Tubercles and hind border of prothorax narrowly, yellowish. 

 Anterior portion of mesothorax curiously ornamented with appressed 

 pure white hairs. Mesothorax appearing granular, microscopically 

 reticulate, with very sparse shallow punctures. 



Legs brown, anterior tibiae and tarsi dull yellow. Tegulae yellow- 

 ish-hyaline. Wings hyaline, nervures white or colorless. Marginal 

 cell with its substigmatal portion fully twice as long as the post- 

 stigmatal. Second submarginal triangular, bulging without, nar- 

 rowing to a point at marginal. Third discoidal distinct. 



Abdomen above sepia-brown, the proximal ends of the first two 

 segments slightly yellowish. Venter dull brownish-yellow. 



Hab. — San Marcial, N. M., on Larrea at the same time and place 

 as P. larrece. Three specimens. 



There are three possibilities regarding the last three species : 



(1). That they are three distinct species. 



(2). That the males represent two valid species, and larrearum 

 the 9 of one of them. 



