OF WASHINGTON, VOLUME XI, 1909 35 



that the species is but narrowly separated from quinquefas- 

 ciatus, if, indeed, it is a true species at all. 



In the genitalia of the typical form (Plate i, fig. 1) the 

 harpes have a small basal projection, larger than in pipiens, 

 but still in a rudimentary condition. The harpagones are 

 divided into three plates ; the second (fig. 1, c) is a rather slender 

 plate about as long as the harpes, with rounded pointed tip ; 

 first plate (fig. 1, d} broad, very long, with bluntly rounded 

 tip; third plate (fig. 1, /) essentially as in pipiens. 



The species is especially characterized by the great length of 

 the central plate of the harpagones, which is not divided into 

 two portions, as in pipiens. 



In the genitalia of the race dipseticus (fig. 3), the first 

 branch of the harpagones is not especially elongated (fig. 3, c). 

 The other characters remain essentially the same, including the 

 flat and pointed condition of the second plate (fig. 3, d). 



Type No. of the race dipseticus, 12229, U. S. Nat. Mus. 



Culex comitatus, new species. 



The genitalia (Plate i, fig. 2) have the general characters of 

 quinquefasciatus, race dipseticus, but differ especially in the 

 character of the second plate of the harpagones (fig. 2, d}, 

 which is no longer a plate, but a -tubular structure, with oblique 

 open tip. The first plate of the harpagones is broad and rather 

 long, with rounded tip, essentially as in dipseticus. The basal 

 projection of the harpes is very short, but this cannot be espec- 

 ially emphasized, as its apparent condition varies greatly with 

 the position of the mount. 



Our specimens are from National City, San Diego, Sweet- 

 water Junction, Laguna, Avalon, Los Angeles, San Pedro, 

 San Luis Obispo, and Stanford University, California, all 

 these places being on the coast, south of San Francisco, or on 

 the adjacent islands. 



It is somewhat curious that the species Culex quinqucfas- 

 ciatus, after ranging throughout the warmer parts of the world 

 unchanged, should, in the arid parts of America, develop first a 

 distinct race and finally a species. This must be of significance 

 in regard to the original home of the species. Evidently quin- 

 quefasciatus is of tropical American origin, and has latterly 

 spread, no doubt through the agency of commerce, to all the 

 warmer regions of the world. In these places it has not been 

 resident long enough to develop local races and species, as it 

 has done in America. Conversely, it is probably that Culex 

 pipiens is of European origin, and has only latterly spread to 

 America through the agency of commerce, 



