190 GASTROPODA. [Pectinibranchia. 



3. Laevilitorina caliginosa, Gould, 1849. Plate 35, fig. 11. 



Hydrobia caliginosa, Gld., P. Bost. S.N.H., iii. 83. Lcevilitorina calirjinosa, 

 Goiild : Martens and Pfeft'er, Jahrbnch Hamburg. Wissench. Anst., 

 1886, 81, pi. 1, f. 8; Man. Conch. (1), ix, 2o4. pi. 46, f. 29. Lillornx, 

 caliginosa, Gould, U.S. Expl. Ex., 198, pi. 14, f. 240. Hydrobia rn/ii/inosa, 

 Gld/: Smith. Phil. Tr. Roy. Soc., clxviii, 1879, 173, pi. 9, f. 8. Pulu- 

 destrina caliginosa, Gld. : E. A. Smith. P. Mai. S., iii, 22. 



Shell small, turbinate, thin and fragile, smooth, dull, rimate. The 

 only sculpture fine, microscopic growth-stria?. Colour chestnut or 

 olivaceous brown. Epidermis thin, not shining. Spire elevated conic, 

 a little higher than the aperture, outlines convex. Protoconch globose, 

 of 1| smooth, polished, and convex whorls. Whorls 4-5, ventricose, 

 rapidly increasing ; base convex. Suture deep. Aperture oblique, 

 oval, rounded above, flattened on the wall ; interior livid or chestnut- 

 coloured. Peristome continuous, thin, and sharp. Columella oblique, 

 arcuate, but little callous. Umbilicus represented by a narrow chink, 

 absent in young specimens. Operculum as in Litoritxi. 



Diameter, 3-3 mm. ; height, 5 mm. 



Dentition. Martens and Pfeffer, I.e., 83, pi. 3, f. 10. 



Type in the U.S. Nat. Museum, Washington. 



Hob. Macquarie Island (A. Hamilton). The type is from Royal 

 Sound, Kerguelen Island. Terra del Fuego ; South Georgia. 



4. Lffivilitorina Hamiltoni, E. A. Smith. 1898. Plate 35, fig. 12. 



Paludestriini HinniUoni, E. A. Smith, P. Mai. S., iii, 22, f. 1, 2 in text. 



Shell very small, subglobose, narrowly umbilicated, smooth, thiu 

 and fragile. Incremental strife form the only sculpture. Colour fuscous. 

 Epidermis thin, not shining. Spire short, obtuse. Protoconch small, 

 flat, mostly eroded. Whorls 3, rapidly increasing, convex, the last 

 predominant ; base rounded. Suture deep, obsoletely canaliculate. 

 Aperture large, roundly ovate, fuscous. Peristome continuous, thin, 

 and sharp. Columella vertical, long, slightly arcuate, not callous. 

 Umbilicus very narrow, a small carina at the base of the area. 

 Operculum of 2^ whorls. 



Diameter Maj., 3 mm. ; min., 2 mm. : height, 3 mm. (type). 



Dentition unknown. 



Type in the British Museum. 



Hob. Macquarie Island (A. Hamilton). 



Remarks. This shell recalls in some respects certain forms of 

 the genus Lacuna. The dentition being unknown, the generic position 

 is uncertain. 



Fain. RISELLID^E, Kcsteven. 



The formula of the teeth of the radula is 3 + 1 + 3 ; the central 

 tooth quadrangular, longer, than broad, with 1 or several cusps ; 

 laterals large, with long narrow bases, and bearing usually several 

 cusps. 



