617 



Shell of a subovatc trigonal form, thin, smooth, the hinder 

 side longer than the front ; the umboues bluish and small. Colour 

 pale ashy-buff, with one strong spot of brown near the hinder 

 angle, and, in one specimen, a number of interrupted brown rays. 



Of the two specimens in the collection of Mr. Hanley, the 

 locality is unknown. 



17. Cytheujea tiugonella (pi. cxxviii. f. 16), Lamarck, 

 Anim. s. vert. no. 28. Trigona angulifera, Qray, in Analyst, 1838. 



Cyth. "testa trigona, suba)quilatera, depressa, pallide fulva; 

 radiis albis, raris ■ ano lanceolato." — Lamarck. 



The specimen figured is very much like that in Delessert (t. 8. 

 f. 3) ; and this is the only means of identification, as the above 

 description would apply to several. It is oblong, trigonal, almost 

 transparent, nearly equilateral ; at the hinder side it is rather 

 squared and has a dark brown band. There is a red softened 

 spot on either side of the umbones, which are small, and the body 

 of the shell is variously coloured with pale rays and several zig- 

 zag brown markings. 



West Indies. 



18. Cythek^a incerta (pi. cxxviii. f. 17), Sowerby, jun. 



Cyth. testa alba, Isevi, ventricosa, ovali-subtrigona ; umbonibus 

 parvulis, utrinque rubro-tinctis ; lineis pallidis, fulvis, angulatis, 

 sparsis. 



A small, white, ovate -subtrigonal shell, resembling C. trigonclla, 

 but more obese and thick, and not so decidedly oval. 



St. John's j M. Ilartweg, We have only seen the specimen in 

 Mr. Cuming's collection. 



19. Cytheilea bicolor (pi. exxvii. f. 10, 11), Gray, in 

 Analyst. Hanley, Sp. of Shells. Wood, Suppl. pi. 15. f. 16. 



Cyth. testa trigona, angulata, alba, post angulum castanea, 

 alta, compressa ; lateribus et margine ventrali rectis ; latere pos- 

 tico subelongato, acutiusculo ; lunula elongata, distincta ; um- 

 bonibus acutis. 



A white shell, with a dark brown mark behind the angle, rather 

 compressed, and nearly approaching an equilateral triangle in 

 form, the hinder side being a little longer and more acute. 



The brown specimen is from the Red Sea, in Mr. Cuming's 

 collection. 



Senegal. 



4 L 



