THE CANADIAN ENTOMOLOGIST 



425 



Fig. 1 



Leptodesmits elrodi, caUflo- 

 ventral view of distal portion of 

 right male gonopod. 



more sloping oft caudad. Caudal corners in about the second 

 to the eighth plates bent moderately forward, then becoming 

 straight in a few and then bent caudad, and in the last few form- 

 ing a distinct but always distally rounded process; edges of 

 lateral carinas narrowly elevated ; 

 pores opening ectad ; nineteenth 

 plate much shortened, its processes 

 reduced; metazonites with transverse 

 furrow distinct; surface to naked eye 

 appearing nearly smooth and shining, 

 under the lens finely . coriaceous, 

 more strongly roughened laterally. 

 Sternites smooth, glabrous. A deep 

 transverse sulcus at middle and a 

 weaker median longitudinal one cross- 

 ing it at right angles. Anal process 

 in dorsal outline subtriangular, dis- 

 tally subcylindric, the tip a little 

 depressed ; a transverse row of four bristles near middle of length 

 and toward and on tip about eight more. Anal scale semilunar 

 in outline, but with the anterior margin weakly convex, bearing a 

 bristle on each side a little in front of caudal margin. Anal 

 valves elevated along mesal border, each bearing a bristle a little 

 ectad of mesal edge near middle of length and a second one in line 

 with it farther caudad. Legs clothed with stiff hairs, which 

 proximally are sparse, but distally, and especially on dorsal surface, 

 become more dense and at the same time shorter. Male gonopods 

 consisting of two long prongs, of which the posterior one is distally 

 slender and style-like and curves evenly, first dorsal and somewhat 

 mesad and then back proximad. The anterior branch just proxi- 

 mad of the curve in the first one expands into a .subtriangular 

 plate on the dorsomesal side, which along its distal or caudal edge 

 bears several short teeth, of which the one at angle is the longest; 

 the prong continues beyond this on a more slender blade which 

 bends abruptly dorsad or dorso-ectad and bears on its proximal 

 edge and mostly on distal portion a series of long, curved, spine- 

 like processes. (See fig. 17). 



Locality. — Montana (Flathead Lake). 



