234 MOSQUITOES OP NORTH AMERICA 



three long branches. Lateral comb of eighth segment of numerous scales in a 

 triangular patch ; single scale angularly elliptical, produced into a long, broad 

 shaft, which is fringed with long spinules. Anal segment longer than wide, 

 ringed by the plate; dorsal tuft of long and short hairs ; a small lateral tuft; 

 ventral brush well developed, limited by the plate. Anal gills small, tapered, 

 not as long as the segment. 



The larvae inhabit the edges of ponds and lakes where protected by vegetation. 

 The species is dominant throughout the arid portion of Forth America, where 

 the standing water becomes more or less stagnant. Dr. Dyar found it throughout 

 the Pacific coast from southern California to British Columbia. All kinds of 

 semistagnant pools are frequented by these larvae, but they seldom take kindly 

 to artificial receptacles, being found only in the open. The adults doubtless 

 hibernate, and bite by night. They may be troublesome in houses; Messrs. 

 Dyar and Caudell obtained specimens in the act of biting out of doors at night. 



Western TTpited States and Canada, extending from the Pacific coast south- 

 ward into Mexico and eastward across the Mississippi River. 



Argus Mountains, California, April, 1891 (A. Koebele) ; San Diego, Cali- 

 fornia, April li-27, 1906 (J. M. French) ; San Rafael, California, July 16, 

 1904 (E. H. Ashman) ; Santa Monica, Los Angeles, and Pasadena, California, 

 May, 1906 (H. G. Dyar) ; Tia Juana, Baja California, Mexico (Dyar & Cau- 

 deU) ; San Diego, Guadeloupe, Dunsmuir, Sisson, San Luis Obispo, and Thrall, 

 California (Dyar & Caudell) ; Stanford University, California (I. McCracken) ; 



Folsom, CaUf omia, July 3, 1885 ( ) ; Carr Canyon, Huachuea Mountains, 



Cochise County, Arizona, August, 1905 (H. Skinner) ; Klamath Lake, Oregon, 

 July, 1906 (Dyar & CaudeU) ; Portland, Oregon (R. P. Currie) ; Victoria, 

 British Columbia, July, 1906 (Dyar & Caudell) ; Kaslo, British Columbia, June 

 23, 1903 (H. G. Dyar) ; Ormsby County, Nevada, July 6 (C. F. Baker) ; Boise, 

 Idaho, August 14, 1901 (C. B. Simpson) ; Colorado Springs, Colorado, April 

 (T. D. A. Cockerell) ; Boulder, Colorado, October 15, 23, ISTovember (T. D. A. 

 Cockerell) ; Grand Junction, Colorado, July 23, August 28, 1906 (E. P. 

 Taylor) ; Denver, Colorado, August (E. S. Tucker) ; Fort Sill, Oklahoma 

 (through C. S. Ludlow) ; Lawrence, Kansas, June (E. S. Tucker) ; Lawrence, 

 Kansas (J. M. Aldrich) ; Dallas, Texas, November 10, 1905 (F. C. Pratt) ; 

 Dallas, Texas, May 11, 1905 (W. D. Pierce) ; Victoria, Texas (E. G. Hinds) ; 

 St. Louis, Missouri, September, 1904 (A. Busck) ; Scott, Arkansas, October 1, 

 1909 (J. K. Thibault, Jr.) ; Urbana, Illinois, September 2, 7, 8, 10, 1904 (F. 

 Knab) ; Ames, Iowa, October 18, 1905 (H. J. Quayle) ; Ensefiada, Mexico (A. 

 Duges). 



This species was first described by Professor WiUiston, but without a name. 

 Giles and Speiser independently proposed names, that of Speiser intended to 

 replace the preoccupied name affinis Adams, but the species had been previously 

 named by Coquillett. The species is conmion in the arid West, becoming less 

 abundant in its eastward range. The larvae from the easternmost localities have 

 longer air-tubes than those from the westernmost, but we think that the various 

 local forms are not specifically distinct. 



The coloration of the adult, as in other species of Cidex, is subject to con- 

 siderable variation. This is particularly true of the thoracic markings, which 

 are often more or less evanescent ; frequently the subdorsal stripes are broken 

 into spots. On the abdomen the dorsal band of the second segment is triangu- 

 larly produced beyond the middle, and on the three or four succeeding segments 

 the bands are broadened towards the middle ; frequently the first three or four 

 bands are interrupted at the sides and do not join the lateral spots. The mental 

 plate of the larva is figured on plate 139, fig. 562. The larva figured by Quayle 

 (I. c, p. 49, fig. 33) as this species belongs to Culex stigmaiosoma. 



