192 Proceedings of the Eoyal Physical Society. 



XX. — A New Flea (Xenopsylla trispinis) from South Africa. 

 By James Waterston, B.D., B.Sc. 



(Read 27th March 1911. Received 27th March 1911.) 



This species belongs to the second section 1 of the genus, the characters 

 of which are — the episternura of metathorax separated from the sternum; 

 the subapical bristle at least as long as the second hind tarsal segment ; 

 hind femur angulate ventrally at the widest point ; fifth segment of fore- 

 and mid-tarsi with three spine-like bristles ventrally at apex ; clasper with 

 two distinct free processes ; manubrium long ; penis without brush near 

 apex. 



Evidently close to X. cheopis, Eothsch. and X. nubicus, Eothsch., but 

 distinguished by the genitalia and tarsi. 



Head — Eostrum reaching apex of forecoxa in $ but falling short in the $ . 

 Eow 2 of 7 or 8 bristles on the occiput. First antennal joint in $ 

 with row of about 10 minute hairs on outer edge and proximally 

 one or two more. In £ these hairs number 6-7 with none 

 behind. At apex of the joint ( £ only) is a single somewhat 

 stronger hair. Above the antennal groove are 3-4 long hairs or 

 bristles in addition to a few minute ones. 



Thorax — 



Prothorax with a row of 8-10 bristles. 

 Mesothorax „ ,, 10-11 „ 



Metathorax „ „ 11-13 



The mesosternite has four or five bristles on each side (one $ with 5 



and trace of 6th). 

 The raetasternum (a) episternite and sternite with one bristle each ; 

 (b) epimeron with 9-12 bristles in two rows, commonly 5, 5, or 

 5, 6 ; but one $ shows 2, 5, and one $ shows 8, 6. The posterior 

 edge is slightly curved and the ventral angle obtuse (c.f. cheopis). 

 Abdomen — 



Tenjites — The first has two rows of bristles, containing about 8 each, in 

 both sexes. The anterior row is irregular, especially in the $ . 

 The second to sixth inclusive have a single row of 18-19 bristles. 



1 " Revision of Non-combed Eyed Siplionaptera," Karl Jordan and N. C. Rothschild, 

 vol. i., No. 1, Parasitology, 1908, p. 42. 



2 Counting both sides and so elsewhere, unless one side is specially mentioned. 



