416 Mr. James Waterston on Chiastopsylla godfreyi. 



slender, broadest near base, greatly 

 exceeding the breadth of the 9th 

 sternite, which bears three pairs of 

 scales distally. 



3. Eighth sternite finger like distally, the 



three scales on the 9th diamond- 

 shaped equal, acutely pointed . 



— Eighth sternite wedge-shaped, the scales 



dissimilar. The uppermost broad, 

 subquadrate, the second deeply and 

 roundly emarginate distally, the third 

 longest pointed spatulatc . 



4. Posterior edge of 7th sternite incised 



about the middle. 



— Posterior edge of 7th sternite entire or 



produced medianly. 



5. Eighth tergite with about a dozen stiff 



bristles on its ventral half, not counting 

 those which stand along the margin 

 posteriorly. Incision of the 7th 

 tergite moderately deep. Metanotum 

 and some of the tergites armed with 

 teeth on hind margin 



— Eighth tergite nearly bare ventrally, 



incision shallow, marginal teeth 

 absent ...... 



6. Seventh sternite with edge posteriorly 



entire, four to five external bristles 

 on hind tibia ..... 



— Seventh sternite with short but distinct 



rounded median lobe, eight external 

 bristles on hind tibia 



numae Rothsch. 



rossi Waterst. 



7iumae Rothsch. 



godfreyi Waterst. 



octavii Rothsch. 



rossi Waterst. 



In the above key by " tergite " and " sternite " reference 

 is made strictly speaking only to half of the sclerites 

 respectively indicated, i. e. to the profile view afforded in 

 a whole mount. Chiastopsylla Rothsch., so far as our 

 knowledge goes at present, is an exclusively S. African 

 (Cape Colony) genus associated with small ground mammals 

 of the genera Mus, Mystromys, Otofnys, Crocidura, Grapho- 

 cularis and Arvicanthis. 



