832 Charles Paul Alexander 



The larvae were conspicuous by their dark coloration and, when placed 



in water, by their active, snakelike movements, in this regard being very 



different from somewhat similar larvae of certain Eriopterini which they 



resemble superficially because of the five subequal lobes surrounding the 



spiracular disk. The indoor pupal period is six days (May 8 to 14, 1917). 



Larva. — Length, 9-1 1 . 2 mm. 



Diameter, 0.75-0.9 mm. 



Coloration dark brown, sutures pale; pale spots on dorsum and on sides of bod}'; spiracular 

 disk pale, lobes marked with darker. 



Form rather stout, terete (Plate XXXI, 132). Body densely covered with a long, appressed, 

 dark pubescence. Prothoracic segment narrowed in front, long, divided into two rings by 

 a faint constriction; mesothoracic and metathoracic segments gradually longer. First 

 abdominal segment shorter than last thoracic segment; abdominal segments 2 to 7 long, 

 each divided into two narrow annuli by a deep constriction which is destitute of hairs but 

 has just before it a sharp, transverse ridge of stiff hairs; short, incomplete ridges of these 

 stiff hairs on dorsum of anterior ring; anterior ring about half as long as posterior ring; on 

 ventral side of each of segments 2 to 7 on anterior ring, a transverse swelling, these swellings 

 becoming more convex and prominent on posterior segments; swellings appearing almost 

 smooth, being covered only with microscopic, roughened points; posterior ring with a sharp 

 ridge of hairs at about two-thirds its length. Chaetotaxy as follows: dorsal segments with 

 short setae at about midlength of posterior ring; a single rather stout, black bristle on pleura 

 of anterior ring, immediately above transverse swellings; a similar seta on posterior ring; 

 two groups of very long, delicate setae on ventral face of posterior ring, one on each side of 

 the ridge of erect hairs; thoracic segments approximately similar to abdominal segments, but 

 sternal setae at about midlength even more prominent. Last segment of body elongated, the 

 spiracular disk (Plate XXXI, 1.36) surrounded by fiv6 lobes; dorsal lobe the smallest, rather 

 blunt, irmer face with a brownish, triangular-oval mark; lateral lobes of medium length, 

 inner face suffused with brown, which is darkest, almost black, on lower edge of lobe; ventral 

 lobes the longest, inner face of each with two broad, parallel, blackish lines, separated by 

 a somewhat narrower pale line; entire disk fringed around with long, dark-colored hairs, 

 which are longest near tips of lobes, where they are strongly recurved, almost pencil-like; 

 fringe continuous between dorsal and lateral lobes, but between ventral and lateral lobes, 

 and between the two ventral lobes, hairs toward base of each lobe very short to lacking; 

 ventral lobes just before tips with a single long sensory bristle. Spiracles large, subcircular, 

 situated at base of lateral lobes, dark-colored, narrowly margined with pale. Anal gills 

 consisting of two pairs of pale, stout, cyHndrical lobes, tapering toward tips, before which 

 there i-s a slight constriction. 



Head capsule massive and compact, of the normal generalized limnobiine type. Labrum 

 large, conspicuous, transverse, densely fringed with long hairs; on epipharyngeal region, 

 a large, dense tuft of moderately elongate hairs on either side of median line. IMentum 

 (Plate XXXI, 133) net completely divided, but with a very deep split behind, a large median 

 tooth, and two smaller teeth on either side; behind (dorsad of) elongate median tooth, a 

 slightly wider flattened lobe whose margins extend beyond those of outer tooth. Hypo- 



