MA1ACOZOA. GASTEROPODA. PECflXIBRANCHIATA. 63 



turns very convex, faintly striated longitudinally and 

 transversely, yellowish-white, with the inside of the 

 mouth yellow. 



2. Flisusc6rneus. Shell oblongo-fusiform, moderately 

 thick, white, with the turns little convex, with distinct 

 longitudinal and very faint transverse strise, and a yellow- 

 ish-grey epidermis. Crfrneus, horny. 



3. Ftisus Laskeyi. Shell ovato-turrite, subfusiform, 

 moderately thick, with a greyish-yellow epidermis, the 

 turns convex, somewhat flattened above, with five large 

 and several smaller longitudinal ridges, and fine trans- 

 verse striae. Named after Captain Laskey. 



4. Ficsus Buchanemis. Shell fusiform, rather thick, of 

 six moderately convex turns, transversely ribbed, with 

 raised spiral lines decussating the ribs, of which there 

 are twelve on the last turn, the aperture oblong, nearly 

 half the entire length. 



GENUS 3. PLEUROTOMA. Shell fusiform, with the spire 

 pointed, the aperture oval or oblong, with an elon- 

 gated, slightly recurved canal, the outer lip with a 

 notch or slit near its upper angle. 



1. Pleur6toma Bdnffium. Shell oblongo-fusiform, 

 rather thick, white, the turns rounded, with numerous 

 thin-edged, laminar, transverse ribs, bent toward the aper- 

 ture. Named from Banff, where it was first noticed. 



2. Pleurotoma Turricula. Shell oblongo-fusiform, 

 thin, white, the turns angulate at their upper part, ribbed, 

 and striate. Named from its resembling a turret or spire. 



3. Pleurotoma Trevellianum. Shell ovato-fusiform, 

 thin, white, the turns angulate at their upper part, ribbed 

 and striate. Named by Dr. Turton after Mr. Trevellyan. 



4 . Pleur6toma decussdtum. Shell elongated fusiform, 

 rather thick, the turns rounded, with transverse ribs, de- 

 cussated by numerous spiral thin laminae. Decussdtus, 

 with Hues crossing each other. 



5. Pleurdtoma reticulatum. Shell oblongo-fusiform, 

 with the spire a little convex in outline, the whorls 

 slightly angulate at their upper part, with numerous 



