CULEX PINAROCAMPA 253 



abundant. Abdomen long, slender, depressed, and somewhat expanded toward 

 apex; white dorsal bands broader, those of sixth and seventh segments greatly 

 dilated at the sides ; lateral ciliation regular, of long and abundant yellowish 

 white hairs. Claw formula, 1.1-1.1-0.0. 



Length : Body about 5 mm. ; wing 4 mm. 



Genitalia (plate 14, fig. 98) : Side-pieces about three times as long as wide, 

 attenuated at the base, a rounded quadrate outer lobe bears three rods with 

 curved tips, a leaf -like appendage, and a seta ; clasp-filament stout at base, some- 

 what curved, with a small terminal claw and a little seta at outer third. Harpe? 

 divided, inner lobe rounded and bearing a crown of stout spines, outer lobe blade- 

 like, curved. Harpagones divided into a number of lamellae. Unci forming a 

 small basal cone. 



Larva, Stage IV (plate 99, fig. 327). Head rounded, wider than long, 

 widest at the eyes; antenna? long, a large tuft at outer third, the part beyond 

 slender ; upper pair of head-hairs in sixes, lower in fours, ante-antennal tuft 

 multiple. Skin glabrous ; lateral abdominal hairs in twos after second segment ; 

 comb of eighth segment of many spines in a triangular patch. Air-tube about 

 six times as long as wide, pecten short and reaching the basal third ; four double- 

 haired tufts beyond pecten, the subapical one moved well out of line; terminal 

 hooks minute. Anal segment little longer than wide, ringed by the plate ; dorsal 

 tuft of several hairs on each side ; lateral hair small, double ; ventral brush con- 

 fined by the chitinous ring. Anal gills long, one gill somewhat longer than 

 the others, all roundedly pointed, about three times as long as the segment. 



The larvjB live in water in holes in rocks in stream-beds, particularly the 

 shallow pools on top of rocks. Mr. Knab first met with the species in the bed of 

 a small river. The banks were precipitous, with overhanging vegetation which 

 was in places very thick. A large bowlder in the dry part of the bed of the 

 stream had a depression on top containing perhaps a gallon of water, which was 

 swarming with mosquito larvae of all sizes. Besides the present species the water 

 contained Aedes epactius and Aedes fluviatilis, both also rock-hole inhabiting 

 forms. Mr. Kna.b found the larvae in six other pools in the same stream ; a pool 

 of clear water, shaded by an overhanging bank and by large bowlders, contained 

 a few larvae associated with Culex derivator and Anopheles strigimacula ; a pool 

 apparently of spring water contained larvae, not very abundantly, associated 

 with Anopheles strigimacula and a Culex, perhaps Culex derivator; a large 

 bowlder, where the rapids passed into a canyon, contained a depression with 

 water very foul from excrement of a predaceous mammal and covered with a thick 

 scum ; in this water were about a hundred pupae and one larva, all of them this 

 species; another bowlder with a shallow depression on top contained about 2 

 quarts of water, the larva? here being associated with Lutzia higotii; again, 

 when there had been no rain for some time, a shallow pool between rocks, main- 

 tained by a percolation of v/ater from the river, contained this species associated 

 with Culex coronator and Anopheles argyritarsis ; a water-hole in the stream-bed 

 containing clear water, with this species, Culex derivator and Anopheles argyri- 

 tarsis. The larvae were also met with in small numbers in other less normal 

 situations ; once in a small ditch of muddy water in a railroad cut near town, 

 where Culex coronator and Aedes cuneatus were associated, and once in another 

 railroad cut where a hole had been filled by recent rains, where Culex coronator 

 and Lutzia higotii were associated. 



Mexico. 



Cordoba, Vera Cruz, larvte in rock-pools along the Rio San Antonio, January 

 4, 20, 22, 31, March 4, April 5, 1908 (F. Knab) ; Cordoba, larvae in pool in rail- 

 road cut, January 26, 1908 (F. Knab) ; Penuela, Vera Cruz, larvae in water-hole 

 beside railroad track, April 22, 1908 (F. Knab). 



