56 MALACOZOA. GASTEROPODA. PECTINIBRANCHIATA. 



turns j the aperture oblong, very narrow behind. 

 Politus, polished. 



4. Eidhna subuldta. — Shell very elongated-turrite, 

 tapering to a fine point, of about ten flat, smooth, very 

 glossy turns, which are white with two brown bands ; 

 the aperture oblong, very narrow behind. Sufaildtus, 

 slender and tapering. 



Genus 7. Lacuna. — Shell ovato-conical, thin, with a 

 delicate epidermis ; the aperture oval or roundish, the 

 peristome incomplete behind, the columella flattened, 

 and forming a deep groove, continued from the umbilicus. 

 Lacuna, a furrow, trench, or hollow. Turton. 



1. Lacuna vincta. — Shell ovate, conical, thin, semi- 

 transparent, with a delicate epidermis, the whorls five, 

 variously coloured, convex, the last somewhat angulate, 

 obsoletely striated transversely, with minute undulated 

 longitudinal striulee ; the aperture roundish-ovate, the 

 columellar groove curved, narrow. Vinctus, girt. 



A. L. vincta quadrifascidta. Four-banded. 



B. L. vincta bifascidta. Two-banded. 



C. L. vincta uniculor. Of one colour. 



2. Lacuna fascial a, — Shell subglobose, broader than 

 long, with the spue depressed, the turns three, very thin, 

 transparent, the last extremely large, with four white 

 and three reddisu-brown bands. Fascidtus, banded. 



3. Lacuna pallidula. — Shell semiovato-globose, sub- 

 conical, thin, of four turus, with the spue very short, 

 and having the margin of the turns sloping towards the 

 suture, the aperture extremely large, ike inner lip ex- 

 tended somewhat in the manner of that of a Nerita. 

 PaUidulus, diminutive o£ pallidus, pale-coloured. 



4. Lacuna sulcata. — Shell subglobose, broader than 

 long, rather thin, of three aud a-half turns, marked with 

 oblique growth-lines at intervals, the *pire very short, the 

 aperture semicircular, extremely large, the inner lip 

 nearly straight, with a very wide umbilical groove. Sul- 

 cdtus, grooved. 



Genus 8. Rissoa. — Shell conical, with the spire elon- 



