192 MEDICAL ENTOMOLOGY 



which are caught by the antennae and crushed between the mandibles. 

 The larva has no stigmata ; the tracheal tubes have, however, two 

 pairs of air sacs, one in the thorax and the other towards the end 

 of the abdomen, which act as floats, and keep the larva suspended 

 horizontally. The last abdominal segment is armed on its ventral 

 surface with a vertical fin, which bears a row of feathered bristles. 

 The pupa floats in an upright position at the surface of water, and 

 has a pair of trumpets on its thorax, not unlike those of the culicine 

 pupa. The end of the abdomen is armed with a pair of broad fins, 

 by which the larva propels itself. 



Annandale has recently described the larva, pupa, and imago (male) 

 of a small gnat, Ratncia inepta, from Peridenyia (4,300 feet), Ceylon. 

 Although the fly has a short proboscis, it has a striking culcinae affinity in 

 that its veins are partly covered with true scales. The larva, which was 

 found in a swamp, is said to resemble somewhat that of the culicid genus 

 Stegomyia ; it has a broad triangular head, long jaw-like antennae, and 

 distinct thoracic segmentation ; floats and fins are entirely wanting. 



Annandale considers that Ramcia inepta is more closely related to 

 the Corethrinae than the Culicinae, but that it links the two groups 

 together. 



SUBFAMILY CULICINAE 



Long slender Nematocera, clothed with characteristic scales. Eyes 

 kidney -shaped and dichoptic ; ocelli absent. Antenna long, with fourteen 

 segments in the female, and fifteen in the male, always pilose in the 

 former and plumose in the latter. Palpi four-jointed, either long or 

 short in both sexes, or short in one and long in the other ; if short they 

 are nearly always straight. Proboscis long and in the female armed 

 for piercing, for the majority of mosquitoes are true blood-sucking 

 insects; in the male it is simple, and is never used for piercing. 

 Scutellum may be simple, consisting of one lobe, or it may be trilobed, 

 and furnished with scales or hairs ; metanotum as a rule well developed, 

 and often covered with scales and hairs. Abdomen long and slender, 

 consisting of nine segments, and for the most part covered with 

 scales and hairs, especially in the male. Female genitalla consisting 

 of two spatulate lateral lobes, covered with scales or hairs. Male 

 genitalia composed of two claspers, each with a large basal lobe, and 

 a variously shaped terminal knee-like joint ; at the apex of the basal 

 segment there is often a well developed spur or spine, which may 

 sometimes be bifid. On the ventral surface of the claspers there is often 



