GENUS MELOPHAGUS 409 



they bury them or merely place them on the surface. Several puparia 

 of Hippobosca maculata have been found in the calf sheds of the 

 King Institute, but it is not clear as to whether they were intention- 

 ally or accidentally deposited there. 



GENUS LIPOPTENA, NITZSCH 



Resembling Hippobosca but distinguished by the presence of three 

 ocelli. 



The flies of this genus are parasitic on deer. Lipoptena cervi, L., 

 a common European species, is parasitic on a large number of 

 different kinds of deer. As usually seen the female is apterous, and 

 it simulates Melophagus ovinus (see below) ; the presence of wing 

 stumps will, however, help to distinguish it from the ' sheep ked '. 

 The male Lipoptena usually has wings, more especially during the 

 autumn months ; Austen points out that the winged males differ from 

 the apterous males in having the abdomen slender, and are of a paler 

 colour. Brumpt has bred several species from the puparia and finds 

 that both sexes possess wings when they emerge ; on finding a host 

 the wings of the female always break off close to their bases. 



GENUS MELOPHAGUS, LATRIELLE 



This genus contains three species, of which Melophagus ovinus, L., 

 the ' sheep tick', ' louse ' or ' ked ' is the best known. 



Melophagus ovinus, L. (Plate LI I, fig. 2.) Head short and broad, 

 fitting closely into the concave anterior end of the thorax ; laterally 

 it is protected by the coxae of the anterior pair of legs. The pro- 

 boscis is long and well developed, but is concealed by the palps ; the 

 front is broader than long and the vertex is nude. The antennae are 

 not very distinct; the eyes are linear, and ocelli are wanting. The 

 thorax is short and flattened ; scutellum rudimentary. Wing promi- 

 nence distinct ; halteres wanting. Abdomen well developed and usually 

 a little more than twice as long as the thorax ; segmentation not 

 visible. Legs strong and covered with hairs ; claws simple. 



This small apterous fly is as widely distributed as its host, with 

 which it has doubtless been carried all over the world. It is nearly 

 always infected with Crithidia melophaga, Flu. ; this true crithidia 

 is of peculiar interest, as it is one of the best-known examples of a 

 flagellate which is transmitted hereditarily. Its life history has been 

 carefully studied by Porter, Swingle, and Flu. . 



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