92 PLEUROTOMID.E. 



Bay near Swansea; one measures three-quarters of 

 an inch in length, and is proportionally broad and 

 stout. An operculum in a Scotch specimen is shaped 

 like a weaver's shuttle, and has the nucleus nearly cen- 

 tral and the lines of growth irregularly elliptical. 



This is the Buccinum costatum of Da Costa, Murex 

 septangulatus of Donovan, and P. cegeensis of Forbes; 

 to these may probably be added the following synonyms 

 — Mangelia Ginnania, Risso, P. Bertrandii, Payraudeau, 

 P. heptagona, Scacchi, and P. costulatum, Cantraine. 

 P. secalinum of Philippi appears to be a dwarf form, 

 having the ribs less angular and the spiral striae more 

 distinct. The name proposed by Da Costa takes prece- 

 dence of that which I have adopted and which is so well 

 known; but we have another still more common species 

 called costata : let the older name, therefore, be con- 

 signed to oblivion, so far as it relates to the present 

 species. 



10. P. rufa*, Montagu. 



Murex rufus, Mont. Test. Br. (i.) p. 263. Mangelia (Beta) rufa, F. & H. 

 iii. p. 454, pi. cxii. f. 3-5, and (animal) pi. TT. f. 4. 



Body white, speckled with chalky flakes, and having a 

 slight tinge of purple : pallial tube rather long : tentacles 

 cylindrical; upper part (above the eye-stalks) extremely 

 short, club-shaped, and of a bluish hue : eyes black and dis- 

 tinct, on the top of thick stalks : foot thick and broad, slightly 

 rounded in front, and bluntly pointed behind. 



Shell oblong -fusiform, solid, nearly opaque, lustreless : 

 sculpture, flexuous and rather narrow longitudinal ribs, which 

 extend to the suture but seldom to the base, and often become 

 indistinct or are entirely absent towards the mouth ; the upper 

 part of each rib is angular ; there are usually 14 or 15 on each 

 of the last five whorls, becoming more numerous and thread- 

 like on the preceding whorl, and disappearing on the top 

 whorls ; the ribs are narrower than their interstices ; the 



* Keddish. 



