172 MEDICAL ENTOMOLOGY 



' hind legs yellowish at the base ; the hairs of the fore and hind femora, 

 ' and particularly on the extensor surface of the hind tibiae, conspicuous. 

 ' Halteres bright yellow ; wings purely hyaline, with delicate and trans- 

 ' parent veins, those of the anterior margin being somewhat thicker and 

 ' more conspicuous ; the wing surface with a golden brown reflection ; 

 ' the media not petiolate. The short, scattered hair of the thorax seldom 

 ' distinct, the colour of the legs variable in intensity.' 



Female. ' In colouring does not resemble the male in the least. The 

 ' ground colour is blackish brown ; the dorsum of the thorax covered with 

 ' a depressed yellow pile, on the margin with a whitish reflection, on the 

 ' centre with a greyish reflection, the pleura greyish white. Abdomen 

 ' somewhat shining ; on the sides whitish or yellowish grey ; on the venter, 

 ' at least at the base, in living specimens, yellow, w^hich is continued 

 ' around on the dorsum in some specimens, usually not distinct in dried 

 ' specimens. Legs brown, usually paler than those of the male ; the 

 ' tibiae, with the exception of the tip, and the fore coxae whitish or 

 ' yellowish white, the tips of the tibiae and tarsi black, the basal half 

 ' of the hind metatarsi and sometimes also the extreme base of the 

 ' following joint yellowish. Front and face grey ; antennae and palpi 

 ' brown, the former paler at the base. In other particulars as with 

 ' the male. Length 2 to 3 mm.' 



Simuliitm teptans is widely distributed throughout Europe, and is 

 stated by Sambon to be the invertebrate host of the parasite (?) of Pella- 

 gra. In this connection it is interesting to note that it is not found in 

 the United States, in some parts of which pellagra is very prevalent. 



SimuUum indicnm, Becker. A large black species (2J mm.), with a 

 dark thorax and abdomen, except the last segments of the latter, 

 which may be yellow or yellowish brown. Femora and tibiae yellow- 

 on their basal halves and black at their apices. It is widely distributed 

 in North India, where it is known as the ' Potu Fly ' ; it is recorded 

 from Baltistan at an altitude of 10,000 feet. 



SimuHum striatum, Brunetti (Plate XXXII, fig. 1). Thorax grey 

 with a few golden hairs, and with three moderately narrow dark stripes 

 commencing just behind the anterior margin, and fading away before 

 the posterior margin is reached ; sides of thorax dull grey. Abdomen 

 black. Fore tibiae dark brown, posterior tibiae yellowish on basal half; 

 hind metatarsi pale yellow with a black tip. This species was. origi- 

 nally described from Ceylon. It is very common in Kodaikanal 

 (6,000 ft.) South India, where.it breeds in all the hill streams. Its egg, 

 larva, and pupa are depicted on Plate XXXII. 



