NO. 1417. RE VISION OF A ME RICA N SIPHONA PTERA—BA KER. 133 



DDD. Labial palpi reaehing beyond the trochanters. 



E. Claspers in male with ventral margin concave and bearing two spines. 



<in'irhn 

 EE. Claspers in male with ventral margin nearly straight and bearing large, 

 long teeth. 



F. Claspers with two teeth r/.w/* 



FF. Claspers with three teeth ciuHnlpi 



CC. Upper genal row of bristles represented only by: 

 D. Two small ones above near the antennal groove. 



E. Two large bristles behind the antennal groove canadensis 



EE. Fonr l)ristles behind the antennal groove euphorhi 



DI). One large one near the genal margin, and one above near the antennal 

 groove; abdominal tergites with three distinctly marked 



rows of usually numerous Ijristles niaskensis 



DDD. One slender bristle on genal margin pro.iiiniis 



BB. Metatarsal article V with but four pairs of lateral spines on tiie margins, the 

 normal basal pair strongly dislocated toward the median 

 line and directed straight distad. 

 C. Metatarsal article I equaling II, III, and IV together, rarely more or less. 

 D. Labial pal])i nearly equaling fore femora: upper genal row with three 



small bristles near the antennal groove, only (icnlatiis 



DD. Labial i>alpi rarely slightly exceeding the trochanters. 



E. Frontal ])art of head with three rows of l)ristles; vertex with at least one 



distinct oV)lique row of bristles .puUiouis 



EE. Frontal part of head with the two usual rows of bristles — at least no 

 more; vertex with no oblique roM's of bristles. 

 F. Hind femur with a well defined lateral row of more than three hairs. 



U. Mesotarsal article I distinctly longer than 11 or V califurnicus 



CtG. JNIesotarsal artit-le I about equal to II and to Y ciliatiis 



FF. Hind femur without a lateral row of hairs on side, though one or two 

 may occur there. 

 G. Pronotal ctenidium with twenty spines or less. 



H. Abdominal sternites with but two bristles on each side; claspers 

 of male with three stout black teeth on expanded middle 



portion of ventral margin wagneri 



HH. Abdominal sternites for the most part witli always more than 

 two bristles on either side; claspers of male not as above. 



I. Mesotarsal article V less than twice the length of IV, II longer 



than V, and I little longer than III leucopus 



II. Mesotarsal article V always about twice IV in length, and the 



other proportions different from above. 



J. Labial palpi abnormally slender labiatus 



JJ. Labial i)alpi normally stout. 



K. Claspers in male with ventral margin bearing four short 



black teeth wickhmnl 



KK. Claspers with five short teeth and one long bristle . .arjills 

 KKK. Claspers with six short teeth and three bristles. 



sexdentatus 

 GG. Pronotal ctenidium with 24-28 spines; the second genal row repre- 

 sented by a few bristles near the antennal groove. 

 H. Metatarsal article II with only three pairs of bristles on dorsal 

 side; hind femur without lateral bristles . .pseudarctomys 

 HH. Metatarsal article II with four pairs of bristles on dorsal side; 

 hind femur with one lateral bristle keeni 



