72 PROCEEDINGS OF THE ACADEMY OF [1896. 



on the shining disc. Wings slightly smoky, nervures and stigma 

 dark brown, stigma not hyaline in middle. Marginal cell short,, 

 distinctly appendiculate, the poststigmatal portion shorter than the 

 substigmatal. Recurrent and transverse cubital nervures broken by 

 hyaline dots. Third discoidal distinct. Cubital and subdiscoidal 

 nervures produced far beyond the cells, the latter to the margin of 

 the wing. Four middle tarsi rufotestaceous, as also the anterior 

 knees, and anterior tibiie before. The light dots on abdomen are 

 inconspicuous, so that it appears at first sight immaculate brown- 

 black. 



Hah. — Fort Collins, Colorado, Aug. 8, 1895, on Solidago canaden- 

 sis ; one example, sent by Mr. Baker. The head is shorter than in 

 affinis, and the pale face-marks are wanting ; the marginal cell is 

 also shorter. 



27. Perdita rectangulata n. sp. Fig. 13, (face-marks). 



$ . — About 5^ mm. long. Head and thorax dark brassy -green , 

 granular, dull ; metathorax bluish. Head of ordinary shape and 

 size. Clypeus, supraclypeal mark, lateral face-marks, and spot mid- 

 way between antennse and middle ocellus, lemon-yellow. Between 

 the supraclypeal mark and the frontal spot, the usual facial keel is 

 well-developed, slightly intruding into the spot. The supraclypeal 

 mark is approximately rectangular, clear cut, about twice as broad 

 as long. The dots on the clypeus are obscure. The lateral fiice- 

 marks are broad at base, reaching the point on the cly- 

 peus next to the dot, gradually narrowing upward, un- 

 til at a point about level with the upper edge of the 

 antennal sockets they are squarely truncate nearly to 

 Fig T' the orbital margin, but still are continued upward along 

 the latter as a narrow stripe a little longer than the 

 width at the truncation. The clypeus is rather of the Panama-hat 

 type, with the lateral narrow prolongation to the base of the mandi- 

 bles, but the central portion (crown of the hat) is higher. The face 

 is nearly hairless. Mandibles stout, simple, curved, pale yellow 

 with dark tips. 



Antennse with the scape entirely yellow ; funicle and flagellum 

 dark brown above, yellow below. 



Mesothorax moderately hairy for a Perdita. Collar, hind border 

 of prothorax and tubercles connecting with it, yellow. Tegulse 

 yellowish-hyaline. Wings hyaline, nervures and stigma pale yel- 

 low ; marginal cell with the poststigmatal portion longest ; 3d sub- 



