322 MEDICAL ENTOMOLOGY 



in its larval stage is found under the skin of the rabbit, causing a 

 large tumour. 



GENUS DERMATOBIA, BRAUER 



The main characters of this genus are summarized in the above key; it 

 contains one species Dermatobia cyaniventris, Macq. (syn. noxialis, 

 Goudot). 



Dertnatobia cyaniventris. Head when viewed from above triangular in 

 shape with the apex directed towards the frontal lunule. Thorax 

 metallic blue, about as broad as it is long, with a dark median stripe, 

 narrowest in front of the transverse suture and broadening out 

 behind it ; in addition there are two dark admedian stripes converging 

 anteriorly towards the median stripe, which they join. There is also 

 a dark curved band situated on each shoulder and a broader one at the 

 sides. Abdomen ovoid, consisting of four visible segments of a metallic 

 blue colour. Length 12 mm. 



This fly is common in South America, where it is known as ' Verma- 

 caque ' ; it normally causes cutaneous myiasis in animals, chiefly cattle 

 and equines ; occasionally it attacks man. The larva is of a characteris- 

 tic shape, narrow and tubular at its posterior end, flask-shaped at its 

 anterior extremity. The eggs are laid on the skin and the larvae burrow 

 into the cellular tissue, where they form a large tumour. 



FAMILY MUSCIDAE 



Small to large flies either of a bright metallic colour without thoracic 

 markings, or greyish black with thoracic bands ; they may be either 

 bare or sparsely covered with hairs; never bristly and rarely elongate. 

 The arista is as a rule plumose on both sides and nearly always to the 

 extremity. The eyes, which are nearly always bare, are more or less conti- 

 guous in the male; in the female they are widely separtaed. Proboscis 

 either long, directed forwards and armed for biting, or folded back and not 

 armed for biting. Abdomen composed of four or more visible segments, 

 the first fused with the second. Venation characteristic ; first posterior 

 cell closed or nearly so, except in the blood-sucking genera, in which it is 

 open to a considerable extent; in the Glossininae the wing venation 

 has undergone a remarkable reduction. The male genitalia are as a rule 

 not prominent. 



The blood-sucking members of the Cyclorrhapha are confined to 

 the Muscidae. In this family there are two notorious insect pests, 



