428 MAZATLAN UNIVALVES 



of her most accurate and careful labourers. Long. '15, long. 

 *pir. *125, lat. '036, div. 11. 



JJab. Mazatlan ; 12 sp. off Chama & Spondylus ; L'pool Col. 

 Tablet 1990 contains the finest specimen. 



520. CHEMNITZIA PSIMILIS, C. JB. Ad. 



Pan. Shells, no. 228, pp. 168, 312. 



There being no type of this species in Mr. Cuming's collec- 

 tion, it is determined with doubt. It is described as differing 

 from Ch. Panamensis in being shorter, with the whirls rather 

 more convex, and the periphery rounder. The apex has 3 

 turns, and projects beyond the margins of the spire. The 

 J.irgest specimen, which has nine whirls, and is beautifully 

 translucent, measures long. '072, lat. '028, div. 20. 

 JTab. Panama ; 2 sp. in the sand ; C. IB. Adams. ? Mazatlan ; 



6 young sp. off Chama and Spondylus ; L'pool Col. 



Tablet 1991 contains the finest specimen. 



521. CHEMNITZIA ACULEUS, C. B. Ad. 



Pan. Shells, no. 219 f pp. 164, 311. 



Shell extremely slender, but with the upper whirls not 

 nearly so pointed as in C. gracillima. The apex in Mr. Cum- 

 ing's type specimen has 3 turns and slightly projects beyond 

 the line of the whirls. These are scarcely convex, with 14 17 

 stout ribs formed by the scooping out of smooth interstices 

 which end on the periphery. The largest specimen, with ten 

 whirls, measures long. '13, long. spir. '108, lat. '03, div. 12. 

 Sab. Panama ; 4 sp. in sand; C. S. Adams. Mazatlan ; 



6 do. off Chama and Spondylus, dead ; L'pool Col. 



Tablet 1992 contains the least worn of the specimens. 



4 



522. CHEMNITZIA MTJEICATA, n. s. 



CJi. t. satis gracili, alba, subdiapJiana ; vertice nucleoso anfr. 

 iii., rotundatis, marginibus spires rectis vix superante, tumente ; 

 anfr. normalibus vii. angustis, planatis, clathratis ; liris cir- 

 citer xvii. solidis, rectis, vix declivibus, plerumque lineis ad 

 apicem decurrentibus ; suturd impressa ; liris ad suturam 

 prominentibus, muricatis ; interstitiis usque ad peripheriam 



