SCOTT— COLEOPTERA, LAMELLICORNIA AND ADEPHAGA 261 



Eretes Castelnau, Ann. Soc. ent. France, i. 1832, p. 397. 



54. Eretes sticticus (Linnaeus). 



Eretes sticticus (Linn.) ; Sharp, On Dytlscidae, p. 699 ; Regimbart, Mem. Soc. ent. 

 Belgique, iv. 1895, p. 208; Linell, Proc. U. S. Mus., xix. 1897, p. 698; AUuaud, Liste 

 Coleopt., p. 70 ; Kolbe, Abh. Senckenb. Ges., xxvi. 1902, p. 573. 



1 male and 3 females : they have a rectangular dark patch, emarginate in front, on 

 the vertex; the transverse dark thoracic band is short and not divided in the middle; the 

 general colouring of the elytra is dark, and the postmedian dark band is not strongly 

 marked ; the elytral fossa of the $ is rather long. They appear therefore to approach 

 near to the var. helvolus Klug. The length is about 13 — 15 mm. 



Loc. Aldabra : 1908—9 (Fryer); 1895 (Voeltzkow), 1893 (Abbott). Cosmo- 

 politan. 

 t 



Cybister Curtis, Brit. Ent., iv. No. 151, 1827. 



55. Cybister tripunctatus (Olivier). 



Dytiscus tripunctatus Olivier, Ent., iii. 40. 1795, p. 14, pi. 3, fig. 24. 



Cybister tripunctattis Sharp, On Dytiscidae, p. 727 ; Linell, Proc. U. S. Mus., xix. 

 1897, p. 699; AUuaud, Liste Coleopt., p. 72; Kolbe, Abh. Senckenb. Ges., xxvi. 1902, 

 p. 572. 



10 males and 3 females from Aldabra agree with Kolbe's description (/.f.) of the 

 subsp. aldabricus in having the yellow border of the same width as in the subsp. afri- 

 canus, in being smaller (ca. 25 mm. long) than most specimens of that subspecies, in being 

 somewhat short, and having the elytra rather conspicuously broadened behind the middle. 

 2 of the females, however, exhibit an excessively fine, but under a powerful lens quite 

 distinct, sexual sculpture on the basal portion of the elytra : in this respect they approach 

 the condition found in the Madagascar form cinctus (Sharp) and in some specimens in the 

 British Museum from the Mascarene Islands. Kolbe states that in the Aldabra females 

 examined by him and included in the subsp. aldabricus, there is no sexual sculpture in 

 the $, which thus approaches nearer to the form africanus. 



Loc. Aldabra: Takamaka, 1907 (Thomasset) ; 1908—9 (Fryer); 1895 (Voeltzkow), 

 1893 (Abbott). Distributed in various forms over S. Europe, Africa, Madagascar and 

 Mascarene Islands, and S. and E. Asia to Australia. 



