WEST AFRICAN GLESSULA. 109 



etriate, the riblets smooth, rounded, and about equal to the 

 intervals. On the face of the last whorl there are five or six 

 riblets in one millimeter. The riblets weaken or disappear 

 almost abruptly at the periphery of the last whorl, leaving the 

 base and a very narrow band above the suture almost smooth. 

 The columella is formed just as in the Indian Glessulae, being 

 deeply concave, thickened with a white callus, and abruptly, 

 deeply truncate at the base. The shell is translucent whitish 

 under a very thin pale yellow cuticle. A specimen of the 

 ordinary size measures, length 20.3, diam. 8.8, aperture 8.3 

 mm.; whorls 6 l / 2 . 



An embryonic shell, shaken out of an adult, is oval, 4.7 

 mm. long, with 3 whorls. There is a distinct umbilical slit 

 behind the columellar callus (pi. 14, fig. 19). 



90. G. BRETIGNEREI Chaper. PL 14, fig. 20. 



Shell thin, transparent, of a light gray-olive tint; shining, 

 though sculptured with very regular, crowded striae of 

 growth, well-marked from the end of the second whorl. Spire 

 of 6 or 7 whorls, very regularly conic after the second whorl. 

 Aperture oblique; columella strongly inflexed towards the 

 interior of the aperture. No umbilicus. Length 30, diam. 

 11 to 12 mm. (Chaper). 



West Africa: Coffee plantation of Elima, Assinie (type in 

 coll. de 1'ficole des Mines). 



Glessula ~bretignerei CHAPER, Bulletin de la Societe Zoolo- 

 gique de France, x, 1885, p. 46, pi. 1, f. 6. Homorus assi- 

 niensis Chaper, KOBELT, Conchyl. Cab. i, lOte Abth., p. 91, 

 pi. 21, f. 6 (copy from Chaper). 



This species differs from G. paritura only by its larger 

 size, so far as the published account goes. Kobelt confused 

 the name with that of Corbula assiniensis, which occurs on 

 the next page of Chaper 's paper. 



91. G. MALAGUETTANA (Rang). PI. 14, fig. 15. 



Shell elongate, conic, thin, subdiaphanous, very minutely 

 longitudinally striate, brown-buff. Apex obtuse. Aperture 

 oval, the columella arcuate, truncate; lip simple, acute. 



