58 Bulletin 29 222 



Localities. — (Exp'd '16) Zones B, D, E, F, G, Rio Gurabo 

 at Iyos Ouemados. (Common). 



Genus Mangilia Risso 



Mangilia maoica, n. sp. 

 Plate 9, Figure 9 



Shell small, turreted, nuclear whorls four, glassy, the last 

 volution carinated and delicately longitudinally ribbed; post-nu- 

 clear whorls four, strongly carinated in young shells but in the 

 adult the last whorl becomes gently rounded, losing the carina; 

 in some specimens the entire surface is adorned with microscopic, 

 frosty, beaded spiral threads alternating with still finer granular 

 lines, in other shells the beaded spirals are inconspicuous over 

 the general surface, but become progressively stronger on ap- 

 proaching the suture, the one bordering the suture being the 

 strongest; whorls with ten undulating ribs, slightly tuberculate 

 at the carina, extending from suture to suture; outer lip thick- 

 ened in adult, sinus U-shaped, deep. Length 4, width 1.5 mm. 



Locality. — (Exp'd '16) Bluff 3, Cercado de Mao. 



Mangilia, Lalonis, n. sp. 

 Plate 9, Figure 10 



Shell with seven strongly carinate whorls, the first two nu- 

 clear, the apical being invariably set at an angle to the main 

 axis of the shell, and the second strongly keeled and delicately 

 ribbed as in the preceding species; post-nuclear whorls five, 

 adorned with straight longitudinal ribs, extending from suture 

 to suture, and numbering nine on the last whorl; spiral sculpture 

 of frosty, beaded threads, with groups of two or three finer be- 

 tween the larger threads; in adult shells the posterior sinus is in- 

 conspicuous; outer lip not thickened. Length of shell 6, great- 

 est width 2.5 mm. 



Closely related to M. maoica, but in this shell the body 

 whorl is strongly carinate, the ribs straight, the sinus inconspic- 



