LACUNA. 269 



L. CARINATA, Jeffreys. PI. 51, fig. 87. 



Thin, opaque, glossy, biangulate, base with a few slight striae, sur- 

 face appearing closely granular under the microscope, white, yel- 

 lowish brown towards the apex ; whorls 5-6, flattened between the 

 suture and upper keel, as well as between the two keels of the body 

 whorl. Length, 2'5 mill. 



Atlantic Ocean (Porcupine Exped.). 



L. CINGULATA, Verrill. PL 51, fig. 93. 



Rather solid, depressed, spirally striated, biangulated, white with 

 a brown nucleus ; whorls 3, rapidly increasing, flattened above and 

 between the carinse ; umbilicus rather narrow and deep. 



Length, 2-2, diam. 3'6 mill. 



Off New England Coast; 906-1467 fms. 



Resembles the preceding species, but is more depressed. Verrill 

 observes that a young specimen, apparently of this species, has a 

 distinct epidermis, bearing small hair-like processes, most prominent 

 on the carinae. 



L. CINCTA, Jeffreys. PI. 51, figs. 88, 89. 



Thin, opaque, glossy, with a few spiral striae, of which one below 

 the suture is more prominent, and mhmtely tuberculated on the 

 upper whorls, white ; whorls 5, convex, with deep suture ; outer lip 

 thin, slightly expanding, folded over the pillar, inner lip attached 

 to the pillar ; umbilicus shallow, enclosed by a semicircular ridge 

 and ending in a small, deep perforation. Length, 2'5 mill. 



Atlantic Ocean (Porcupine Exped.) 



L. NATICIFORMIS, Jeffreys. PL 51, figs. 90, 91. 



Obtusely triangular, with excentric spire, thin, semitransparent 

 and glossy, with a few rather strong basal striae, besides the umbili- 

 cal ridge, white ; whorls 3, convex, rapidly increasing ; umbilicus 

 rather large, with a small, deep perforation. 



Length, 1'75, diam. 2'75 mill. 



Atlantic Ocean (Porcupine Exped.) 



L. OLIVACEA, Verrill. PI. 51, fig. 92. 



Thin, translucent, with 4 convex whorls, the suture scarcely im- 

 pressed, smooth, glossy, covered by a greenish yellow, thin, closely 

 adherent epidermis ; imperforate. Length, 4 mill. 



Off Martha's Vineyard, Mass. 



