268 LACUNA. 



Supposed by Jeffreys to form a connecting link between Adeor- 

 bis and Fossarus. 



L. AZONEA, Brusina (unfigured.) Mediterranean Sea. 



L. Crosseana Kleciak, L. Petitiana, Tiberi, L. mutabilis, Costa, 

 are synonyms. 



L. EXCAVATA, Monts. (unfigured.) Palermo. 



L. Monterosati, Granata, is a synonym. 



Section Stenotis, A. Ad., 1863. 



L. LAXATA, A. Ad. PI. 50, fig. 77. 



Oval elongated, compressed, thin, whitish, si)ire small, pointed, 

 whorls 3, flattened, rapidly increasing, the last one large, inflated, 

 dilated in front, umbilicus large, open, defined by an angle. 

 Length, 2 mill. 



Japan- 

 Section CiTHNA, A. Adams, 1863. 



L. TENELLA, Jcffi-eys. PI. 51, figs. 84, 85. 



Thin, semitransparent, glossy, without epidermis?, with a few ir- 

 regular, microscopic, spiral lines on the body whorl, white, yellowish- 

 brown at the apex, which is abruptly truncated ; whorls 5, convex, 

 gradually enlarging ; aperture somewhat expanded and angulated 

 at the base. Length, 3 mill. 



N. of Hebrides Is., in 189 and 650 fms., Mediterranean, Azores, 

 Pernavibuco, and E. of Japan ; 114-2050 fms. 



Var. MARGARiTiFERA, Watsou. Fig. 85. 



More or less strongly striated lengthwise, especially on the upper 

 whorls. 



Dr. Jeffreys thought this identical with and a synonym of his 

 var. costulata; granting the identity, the Jeffreysian name should 

 become the synonym, being latest published. 



L. Adamsi, Jeflfreys. PI. 51, fig. 86. 



Thin, semitransparent, glossy, no sculpture except the umbilical 

 ridge, white; whorls 4;!, moderately convex, rapidly increasing, 

 with dee[) suture ; umbilicus narrow, enclosed by a sharp ridge. 



Length, ]'5 mill. 



Atlantic Ocean, (Porcupine Exped.). 



