PLEUROTOMA. 379 



found in the Bute deposit by Mr. Crosskey is erroneous. 

 Its present distribution is mostly southern although 

 Loven and Malm have dredged it in the south of Sweden, 

 and Sars has recorded it with doubt from Oxfjord 

 Atlantic coasts of France, Spain, and Portugal, from 

 Boulogne to Gibraltar ; Teneriffe (M f Andrew); Mediter- 

 ranean, Adriatic, and ^Egean : depths 2-40 f. 



This elegant shell differs from P. striolata in being 

 more slender, and highly polished ; the ribs are not an- 

 gulated at the top, nor is the spire turreted ; the surface 

 is smooth ; and the linear markings are very peculiar. 

 My finest specimen (for which I am indebted to the 

 kindness of Dr. Battersby, who dredged it at Torquay) 

 is three-quarters of an inch long. 



It appears to be the Mangelia striolata of Risso, P. 

 Villiersi of Michaud, P. gracilis of Scacchi, and P. nu- 

 perrimum of Tiberi. 



3. P. COSTA'TA*, Donovan. |p\ 90 . 



Murex costatus, Don. Br. Sh. iii. pi. xci. Mangelia costata, F. & H. iii. 

 p. 485, pi. cxiv. A. f. 3-5, and (animal) pi. RR. f. 4. 



BODY clear white, with a bluish tinge, more or less closely 

 speckled with light purplish-brown or yellow, or with irregular 

 flakes of milk-white : pallial tube cylindrical, rather long and 

 flexible, exhibiting a notch-like fold at the opening : tentacles 

 rather short, with bulbous tips, doubled in thickness for the 

 lower half by the eye-stalks: eyes rather large, placed on 

 swollen terminations of the stalks : foot elongated, narrow, and 

 thick, in front truncated, gently curved, or slightly indented 

 with small angular corners, attenuated and finely pointed be- 

 hind ; when the animal is at rest, the sole is strangulated or 

 divided across in the middle: [odontoptiore, pleural spine 

 strong, with the head or top folded back, and the side indented 

 and gaping or incurved. (Loven.)] 



SHELL agreeing in many particulars with that of P. atte- 

 * Ribbed. 



