T. D. A. COCKKRELL. 15o 



scopieally sculptured with tine grooves, in part modified into a minute tessellation : 

 mesotliorax nude, dullish, sculptured like the vertex, median impressed line dis- 

 tinct ; scutellum and base of metathorax similarly sculptured, as also the pleura ; 

 tegulse testaceous. Wings hyaline, nervures and stigma piceous; stigma very 

 poorly developed, narrow, running to a fine point: marginal cell obliquely trun- 

 cate, with a very short ajjpendicular nervure ; poststigmatal portion somewhat 

 the larger: second submarginal narrowed more than half to marginal: third 

 discoidal distinct. Legs with thin, whitish pubescence. Abdomen of ordinary 

 shape, moderately shining, minutely sculptured in the same manner as the thorax ; 

 pollen is carried on the hind legs and on the venter of the thorax, quite a quantity 

 in the latter position. 



Hab. — Two specimens in Soledad Canon, Organ Mountains, New 

 Mexico, August 15 on plant No. 41, a small composite with deep 

 yellow flowers (C. H. T. Townsend). 



In my key to Perdita (Proc. Phila. Acad., 1896, p. 45) this runs 

 down to 20, where it is distinguished by the black head and thorax, 

 and small size. It is a very peculiar and distinct little species, inter- 

 mediate between Perdita s. str. and Macrotera. 



(17.) Perdita. i'allicerala n. sp. %. — Length 4^ mm. Head and thorax 

 shining, very dark indigo-blue, vertex slightly inclined to be greenish ; both head 

 and thorax with sparse, but long and conspicuous white hairs, denser on face 

 and cheeks; cheeks unarmed. Head fairly large, broader than long: clypeus 

 very low, black with an geneous tinge, the anterior margin broadly creamy white ; 

 on each side of the clypeus is an equilateral triangle of the same aeneous black, 

 and the extreme corner between the eye and the mandible is cream color ; labrum 

 bilobate, pellucid white; mandibles slender, simple, white with the ends rufous, 

 and a black basal tubercle ; scape and funicle piceous, pallid at ends; flagellum a 

 beautiful sulphur-yellow, with the first six joints more or less ringed with piceous 

 above; eyes piceous: vertex minutely granular. Thorax without light marks; 

 tegulse hyaline, colorless, with an opaque spot in front. Wings hyaline, nervures 

 and stigma yellowish white; third discoidal cell absent, though in certain lights 

 the faintest indication of the missing recurrent nervure is perceptible; marginal 

 cell with the substigmatal portion perhaps slightly the longer; second submar- 

 ginal much narrowed above, approaching an equilateral triangle, the lower inner 

 corner truncate ; coxse black, with the ends yellowish ; trochanters black, femora 

 black, with the knees pale yellow, anterior tibise all yellow, middle tibise yellow, 

 with a black patch in front and a shade behind ; hind tibise yellow at ends, black 

 in middle, with long white hairs; tarsi pale yellow, claws dark at their strongly 

 bifid tips. Abdomen dark sepia brown, segments 1-.5 with cream-colored bands, 

 which are broadly sublaterally notched above on each side, so as to be for a space 

 narrowed to a fine line, and seeming interrupted until examined with a strong 

 lens; laterad of this the bands rapidly widen, and are confluent at the extreme 

 sides; sixth segment pale; apex pale orange; venter entirely pale yellowish, 

 except the first segment, which is black. 



Hab. — Las Cruces, New Mex., Aug. 21, 1896, two on plant No. 

 44, which I take to be Baileya maltinidlata (C. H. T. Townsend). 



TKANS. AM. ENT. SOC. XXIV. (20) JUNE, 1897. 



