166 INSECUTOR INSCITI^ MENSTRUUS 



rather as an accident. In the male hypopygium, the spine at 

 the basal lobe of the side piece is slightly more outwardly 

 placed than in lazarensis, but the character does not appear 

 equally distinct in all mounts, and is too indefinite for a posi- 

 tive separation. The other male characters are alike. In the 

 larva the upper pair of head hairs show a tendency to be mul- 

 tiple, but subject to the usual variation. I do not consider the 

 character to be necessarily specific, though indicating a racial 

 distinction. 



In the high land about Lake Tahoe, where the large open 

 snow-pools occur, the tahoensis adults are large and distinctly 

 marked. Farther to the north, conditions being less favorable, 

 the adults are small, and the dorsal markings more or less con- 

 fused. The appearance reminds one of impiger (decticus), 

 but the male hypopygium remains normal. In the high land 

 about Mount El well (Feather River region), the species was 

 abundant, but only a few large specimens were seen. At 

 Crater Lake they were small with confused markings, and not 

 abundant, being largely replaced by masamae, discussed later. 

 The species thus has its main center about Lake Tahoe, and 

 degenerates northward. 



Additional data are as follows : Summit, Placer County, 

 California, June 12-20, 1920 (H. G. Dyar) ; Tahoe City, Cali- 

 fornia, June 16, 17, 18, 1920 (H. G. Dyar) ; Gold Lake, Sierra 

 County, California, June 26, 1920 (H. G. Dyar) ; Camp Elwell, 

 Plumas County, California, June 23-27, 1920 (H. G. Dyar) ; 

 Crater Lake, Oregon, July 28-30, 1920 (H. G. Dyar). 



Males were observed swarming at Camp Elwell, the habits 

 being the same as with hexodontus, described later. 



Aedes (Heteronycha) masamae, new species or variety. 



Female. Large ; mesonotum with dark bronzy brown scales 

 over the anterior portion, the scales about the antescutellar 

 space and the roots of the wings whitish ; two blackish stripes, 

 broad in front, narrow and a little curved behind ; short side 

 stripes similar, moderate, bent on the lateral suture. Head 

 dark, with small patch of whitish scales on the vertex and 

 larger one on each side. Abdomen black scaled, with narrow 



