REPORT ON MOSQUITOES. 363 



sides. The mentum is very broad and unlike Cnlex, is joined 

 with a suture to the ventral sclerite of the head; on its anterior 

 margin are six to eight large teeth, alternated with small ones. 

 The eyes are small black spots, situated on the sides of the head 

 anterior of the transverse row of spines. 



The thorax is white at the neck, and with two narrow white 

 stripes crossing the dorsum, the posterior one divided centrally. 

 It is a little broader than long, with six lateral tufts of rather 

 long hair, the anterior two tufts small, the posterior ones larger 

 and issuing from pointed fleshy processes. 



The abdominal seginents are transversely oblong in the an- 

 terior part, becoming very narrow posteriorly; the lateral two 

 tufts in the first two segments arise from acute processes like 

 those of the thorax, the succeeding ones shorter and smaller, aris- 

 ing from only slight prominences which diminish in size pos- 

 teriorly. Two transverse white lines on each segment, cross the 

 abdomen near or at the connecting sutures, and a small brown 

 spot is enclosed within. Tlie seventh segment bears the anal 

 siphon which is about two and one-half times as long as broad, 

 with sides parallel their entire length and a few cun^ed spines at 

 the apex. The ninth segment is slightly longer than broad, with 

 a double dorsal tuft of long hair and a scant ventral brush of 

 equally long- hair. The tracheal gills are veiy short, much less 

 than half the length of the ninth segment. 



Habits of the Early Stages. 



The larvae of this little species were first found at Lahaway by 

 Mr. Brakeley and myself, June i, 1901, in a cold spring pool. 

 They were utterly unlike any other mosquito larvae known to me 

 and yet seemed to be essentially Culicids. From the prominent 

 head Mr. Brakeley dubbed them "Bull-heads"; from the shape 

 I called them "triangles." These specimens were kept alive for 

 a few days only and were very sluggish. July 27th, Mr. Brake- 

 ley found a little group of them along the shallow edge of a lily 

 pond among the grasses and some of these pupated on the 28th 

 and 29th, forming a pupa as odd in form as the larva itself. Un- 

 like all the other Culicids this pupa floated horizontally on the 

 surface, almost motionless and drowned readily; it resembled 

 most nearly the chrysalid of some Lyc?enid butterfly in miniature, 

 and but for the breathing tubes, would never have been suspected 

 of mosquito affinities. When the adults were obtained, four and 

 one-half days later, they proved to be not only specifically but 



