5-jO CALIFORNIA ACADEMY OF SCIENCES. 



(straight in the male), and with the transverse abdominal 

 blotches of the first three or four segments broken in the 

 middle and the lateral parts projecting diagonally inward 

 and backward ; in the male the blotches run evenly across 

 the segments. I figure the male. 



Nitzschia dubius n. sp. (Plate lxxiii, fig. 6.) 



A few specimens from the Chimney Swift, Chcctura 

 ■pelasgica (Lawrence, Kansas). Much like Nitzschia 

 pulicaris, Nitzsch, from the European Swift, Cypselus 

 opus, but differs in lacking the pustulated hairs of temples 

 and abdomen, and in the shape of the metathorax. The 

 specimens are in poor condition and permit of only an 

 unsatisfactory description. 



Body, length 2.22 mm., width .88 mm.; elongate, with 

 narrow neck-like prothorax; expanded posterior portion 

 of abdomen with numerous very long hairs; head, thorax 

 and legs pale, abdomen much darker. 



Head, length .41 mm., width .72 mm.; shape of head 

 of pulicaris, that is, triangular, with rounded front, a 

 shallow concavity of the margin where the palpi project, 

 a shallow ocular emargination, with conspicuous ocular 

 fringe and expanded temples, the margins angulated in 

 front and behind; the margin of forehead with six hairs 

 on each side, the third and sixth being long; the temporal 

 margins with four long hairs weakly pustulated, and a 

 few very short hairs or spines; occipital margin concave, 

 straight in middle, with four longish hairs; ground color 

 pale tawny, with very small, black, ocular flecks, weakly 

 colored, small, brownish, ocular blotches, strongly colored 

 mandibles, and a weakly colored region outside of each 

 mandible. 



Prothorax subquadrangular, with shortly produced rec- 

 tangular angles in lateral margins before the middle, each 



