316 INSBCTA. 



at almost every season of the year. In coitu tliey are united end to 

 end, and frequently fly in that position. Some of the females commit 

 their ova to the water ; others deposit them in the earth or on plants. 



The larvae, always elongated and resembling worms, have a squa- 

 mous head, always of the same shape, the mouth of which is furnished 

 with parts analogous to maxillfe and lips. They always change their 

 skin to become nymphs. The latter, sometimes naked, and sometimes 

 enclosed in cocoons constructed by the larvse, approximate in their 

 figure to the perfect Insect, present their external organs, and com- 

 plete their metamorphosis in the usual manner. They have fre- 

 quently, near the head or on the thorax, two organs of respiration, re- 

 sembling tubes. This family is composed of the genera Culex, and 

 Tipiila of Linnaaus. 



Some, in which the antennee are always filiform, as long as the tho- 

 rax, densely pilose, and composed of fourteen joints, have a long, pro- 

 jecting, filiform proboscis, containing a piercing sucker, consisting of 

 five setoe *. They constitute the genus 



CuLEx, Lin. — CuLiciDEs, Lat., 

 Or the Mosquetoes, where the body and legs are elongated and airy ; 

 the antennae densely pilose, the hairs forming tufts in the males ; the 

 eyes large and closely approximated or convergent at their posterior 

 extremity ; the palpi projecting, filiform, hairy, as long as the probos- 

 cis, and composed of five joints in the males, shorter and apparently 

 with fewer articulations in the females. The proboscis is composed 

 of a membranous, cylindrical tube, terminated by two lips, forming a 

 little button or inflation, and of a sucker consisting of five squamous 

 threads, which produce the effect of a sting. The wings are laid ho- 

 rizontally, one over the other, on the body, with little scales. 



The torment we experience from these Insects, particularly in the 

 vicinity of low grounds and water, where they are most abundant, is 

 well known. Thirsting for our blood, they pursue us everywhere, 

 penetrate into our dwellings, particularly in the evening, announce 

 their presence by a peculiarly sharp hum, and pierce our skin with 

 the fine setse (dentated at the extremity) of their sucker ; in propor- 

 tion as they sink them into the flesh, the sheath bends towards the 

 pectus, and forms an elbow. They distil a venomous fluid into the 

 wound, which is the cause of the irritation and swelling experienced 

 from their attacks. It has been remarked that wc are only persecuted 

 by the females. In America, where they are known by the names of 



* They have been well represented by Reciumur and lloffredi. The figure given by 

 M. Robineau Desvoidy, in his Essai sur la tribu des Culicides — Mem. de la Soc. 

 d'Hist Nat., Ill, 390 — conveys a wrong idea of the disposition of these settc. This 

 writer has promulgated an opinion relative to the correspondence of these parts with 

 their sheath, almost diametrically the reverse of that which is generally received. 

 Had he reflected that two of these setre, in the Syrphi and otlier Diptera, are an- 

 nexed to the palpi, he would not have taken them fer mandibles, but considered them 

 as analogous to jaws. 



