550 MEDICAL ENTOMOLOGY 



gonopodes is rectangular, and usually longer than broad ; there is no sub- 

 segmental plate. 



H. biifali, de Geer, is found on the cape buffalo. Its head is marked by 

 a deep sinus behind the antennae, which divides it into two parts, of 

 which the anterior is the longer. The terminal joint of the antenna is 

 truncated and darker than the others. The sternal plate is trapezoidal 

 in shape, with its broadest side anterior. Each abdominal segment from 

 the second to the seventh bears a conical process, inclined backwards, 

 at the summit of which is placed the stigma. On the dorsal surface 

 there are two parallel brown bands, extending from the anterior edge 

 of the thorax to the seventh segment of the abdomen ; these are sepa- 

 rated from one another by a space equal to their breadth ; on each side 

 of the abdomen, external to these, there is another narrower band ; none 

 of these bands is interrupted at the suture between the segments. 

 The genital plate of the male covers the four last segments on the ventral 

 surface ; it is broad in front, narrow behind, with sinuous lateral borders, 

 which are sharply indented in the posterior half ; it bears a row of six 

 long hairs parallel to its anterior border. 



H. (Linognathus) vituli, Enderlein, is found on cattle in Europe and 

 in India, and probably in other parts also. In Madras it is sometimes 

 found in very large numbers on calves, often to such an extent as to 

 seriously injure the hide. Animals harbouring such large numbers are 

 usually thin and weakly. The species will be recognized from its 

 habitat and the key to Enderlein's genera, as it is the only species of 

 Linognathus which occurs on cattle. The distal end of the abdomen of 

 the female is figured on Plate LXVI, fig. 3. 



H. (Solenopotes) caplllatus, Enderlein, was described from cattle at 

 Leipzig. It is the only species of its subgenus. (See key.) 



H. (Polyplax) spinulosits, Burm, is found on Mus decumanus, Mus 

 alexandrinus, and Mus sylvaticus, and is of special interest as being a 

 transmitter of Trypanosoma lewisl from rat to rat. Neumann gives the 

 following short description. Pleurae small ; those of the second to fifth 

 segments of abdomen approximately triangular, with the base posterior, 

 irregularly and finely dentated, with two short thick unequal bristles, 

 the dorsal angle forming a short spine, the ventral rounded ; sixth and 

 seventh oval, with two long hairs. Sternal plate a little longer than 

 broad, pear-shaped, and very slightly coloured. 



H. (Polyplax) stephensi, Christ, and Newst., (Plate LXVI II, fig. 4) is 

 found on the Indian jumping rat, Gerbilhis indicus, and is probably the 

 transmitter of the interesting haemogregarine with which that animal 



