South- African Species of Cossonus. 393 



Corynemerus^ Phlceophagus^ &c., as well as various Nitklulidas, 

 Staphyllnidfe, and some dipterous larvas. These in turn 

 attract the predaceous Ilisteridto of such genera as Ilololepta, 

 PachycrceruSy Placodes, and Epitchinus, wliich doubtless 

 prey on the Cossoni as well as on the other insects. 



It will probably be found that most of the species have a 

 fairly wide distribution. This is certainly the case with 

 C abscissus, Boh., which ranges from Algoa Bay to the 

 Equator and across the continent to Camerun. C. suturalis, 

 Boh., has also been found both in Natal and on the (/ongo, 

 but has not hitherto been recorded from any intermediate 

 localities. 



Synoptic Key for the South- African Species 0/ Cossonus. 



1. (24.) Rosti'iim more or less strongly dilated 



in the apical half. 



2. (7.) Intervals on elytra hearing rows of 



punctures. 



3. (4.) Prothorax very deeply incised near apex, 



hipartite ; the intervals near the su- 

 ture carinate, much narrower than 

 the strife 1- C. abscissus, Boh. 



4. (3.) Prothorax simply constricted near apex, 



not incised ; the intervals near the 

 suture plane, as broad as the striaj. 

 0. (6.) Prothorax without any discal impres- 

 sions or a central carina ; rostrum very 

 gradually dilated from base to apex . . 2. C. Sheppardi, sp. n. 



6. (o.) Prothorax with a distinct carina and a 



longitudinal basal impression on each 

 side of it ; rostrum suddenly and very 

 strongh' dilated at apex 3. C. cariaicollis, 



7. (2.) Intervals on elytra impunctate. [Fabr. 



8. (21.) Prothorax distinctly impressed or cari- 



nate on the disk. 



9. (20.) Rostrum without any central furrow 



above. 



10. (19.) Elytra with only 9 complete slrite and a ' 



short subhumeral one ; the central im- 

 pression on prothorax not interrupted 

 transversely. 



11. (14.) Prothorax with the smooth discal areas 



finely and sparsely punctured. 



12. (13.) Prothorax subpyriform, the sides gradu- 



ally dilated from apex to beyond 

 middle ; metasternum evenly but 

 sparsely punctured 4. ('. africaniis, Boh. 



13. (12.) Pnjthorax subquadrate, the sides rapidly 



dilated from apex to before middle, 

 thus I'orming a distinct shoulder ; 

 metasternum with a large central im- 

 punctate area 5. C. incivilis, Fabr. 



Ann. cL- May. N. Hist. Ser. 7. Vol. xv. 27 



