1/2 MALACOZOA. GASTEROPODA. PECTINIBRANCHIATA. 



Very common in deep water, on hard ground, off Aberdeen; 

 and frequently brought up by the lines, but seldom alive ; the 

 dead shells usually occupied by Pagurus Bernhardus. Found 

 also at Peterhead, Gamrie, and Banff. 



Murex Turricula. Mont. Test. Brit. 262. PI. 9. f. 1. Murex 

 angulatus. Donov. Brit. Sh. PI. 156. Fusus Turricola. Flem. 

 Brit. Aniin. 349. 



3. Pleurotoma Trevellidnum. Trevellyan's Pleurotoma. 



Shell ovato-fusiform, thin ; with the spire tapering to a fine 

 point ; the whorls angulate at their upper part, giving the spire 

 a remarkable scalar appearance, and marked with numerous 

 transverse narrow ribs, and very numerous slender longitudinal, 

 nearly equal raised lines ; the mouth ovato-oblong, with the 

 outer lip thin, and having a distinct notch near its upper angle, 

 the canal rather short ; the colour of the exterior yellowish- 

 white, of the mouth white. Length seven-twelfths of an inch, 

 breadth three-twelfths and a half. 



First distinguished by me in October, 1842, among speci- 

 mens of Fusus Turricula, from deep water off Aberdeen. It 

 very closely resembles that shell, but differs in having both 

 the ribs and striae much more numerous, in being broader in 

 proportion to its length, and in having a more distinct notch 

 in the outer lip. I much suspect however that it is merely 

 . a variety of the species mentioned. 



Pleurotoma Trevellianum. Turton, Mag. Nat. Hist. vii. 351. 



4. Pleurotoma decussdtum. Decussated Pleurotoma. 



Shell elongated fusiform, rather thick ; with the spire taper- 

 ing to a fine point ; the suture distinct ; the whorls rounded, 

 with transverse ribs, narrower than their interstices, and nu- 

 merous spiral thin laminae traversing the interstices, and decus- 

 sating the ribs, on which they form small oblong tubercles ; the 

 mouth ovato-oblong, with the canal very oblique and elongated ; 

 the colour yellowish-white. 



The only specimen I have obtained at Aberdeen is a dead 

 and mutilated shell, a quarter of an inch long, but with the 

 tip of the spire and the tail broken off. Another, complete, 

 excepting the outer lip, was found by me, in August, 1842, in 

 a fishing-boat at Boddam, near Peterhead. It appears to agree 

 with Captain Brown's Fusus decussatus, which he says was 

 found at Killough, in the County of Down, Ireland. The 

 Aberdeen specimen was brought up from deep water by a 

 fishing-line, in the Winter of 1841-2, 



