164 MEDICAL ENTOMOLOGY 



is almost entirely devoid of bristles, but it has well developed spines 

 at the sides of the abdominal segments, and knob-like processes on 

 their dorsal surfaces. There is a pair of long breathing trumpets 

 which arise from the sides of the mesothorax, their stalks are very 

 narrow and are armed with several small blunt processes. The trumpets 

 end somewhat like those of the pupae of the Culicinae. There are, 

 in addition, several protuberances with hairs and spines at their extre- 

 mities, and minute processes on the thorax. The pupa, which never 

 has the larval skin attached to it, anchors itself by two prominent 

 terminal spines; or it may float on the surface. The flies hatch out 

 in three days. 



Lutz in a recent paper records having found the larvae of Cull- 



coides in a variety of situations. The larvae of several species were 



taken from crab holes on the margin of a mangrove 



*. y swamp, where they were living on the decaying 

 Stages : Breeding 



Technique iood * the crabs. Other species were common m 



the salt water around the mangrove shrubs, as well 

 as in the slimy matter at the edges of the swamps. In searching 

 for the larvae in localities where the flies are common, green vege- 

 table matter at the edges of streams should be collected and broken 

 up in some water in a white tray ; if there are any larvae in it 

 they will be seen swimming about in the water. They should be 

 transferred to a watch glass containing water and some of the green 

 vegetable matter in which they were found by drawing them up 

 with a pipette. In two or three days the pupae will be seen 

 floating on the surface of the water at the edges of the watch glass. 

 The larvae sometimes lie motionless at the bottom of the glass ; these 

 are not dead but are pupating, and will soon float up to the surface. 

 The pupae should be transferred to a piece of moist filter paper and 

 placed in a tube plugged with moist cotton wool. The flies, when they 

 hatch, can be fed without difficulty on the shaved surface on the 

 abdomen of a calf. Some specimens should be placed in two per cent 

 solution of caustic potash for mounting, as this is the best way to 

 study the structure of the legs. 



GENUS JOHANNSENIELLA, WlLLISTON 



(Synonyms Ceratolophus, Kieffer; Sphaeromyias, Stephens.) 



Allied to Ceratopogon and Culicoides. All the femora are without 

 spines ; the hind tarsal joints may be hairy or spinulose in both 



