64 PECUNIAE. 



portionate size of the ears. A single valve which I 

 dredged off Skye in 1847 somewhat resembles Philippics 

 var. 77. of P. polymorphus ; the front of each valve is 

 folded inwards and grooved, with the inside margin 

 finely notched or crenulated. In young shells the sur- 

 face is regularly cancellated. The fry is glossy and has 

 very prominent beaks ; its sculpture consists of nume- 

 rous microscopical longitudinal strise on the upper 

 valve, and equally minute transverse strise on both 

 valves. 



A dozen names have been given by different concho- 

 logists to this species. If the authority of O. F. Miiller, 

 the original discoverer, were at all questionable, Gme- 

 lin's name of hybridus would have the priority over that 

 of Danicus, which was proposed by Chemnitz nineteen 

 years after the publication of the Prodromus to the 

 1 Zoologia Danica/ 



P. glaber of Pennant and Montagu is a well-known 

 Mediterranean species ; and there does not seem to be 

 any reason for supposing that it ever inhabited the 

 Welsh or Scotch coasts, as stated by those authors. 



I have a single valve of P. sulcatus, Miiller, which was 

 dredged off the east coast of Shetland by Mr. Barlee ; 

 but as it is an imperfect specimen, I do not at present 

 describe this species as British, but merely offer a short 

 notice of it. It has thirty-two ribs, besides small inter- 

 mediate ones ; they are rounded and cord-like, with 

 thin transverse plates in the interstices. The colour of 

 my specimen is orange-yellow. The ears are propor- 

 tionally larger than in P. septemradiatus. The inside 

 is marked by furrows, which correspond with the ribs 

 as in P. glaber. The species now noticed inhabits the 

 Scandinavian seas. A small single valve, in a semi- 

 fossil state, was taken by Capt. Hoskyns at a depth of 



