CRENELLA. 205 



got it from the fishing-boats." Rare at Scarborough 

 (Bean). Lieutenant Thomas has taken it in seven fathoms, 

 off the Dudgeon, in the Frith of Forth, and in Orkney. 

 It has occurred at Oban in eighteen fathoms, on the west 

 coast of Zetland in seventy fathoms, and on the same coast 

 as deep as ninety at a distance of thirty miles from shore, 

 (M 'Andrew and E. F.) Mr. Jeffreys has taken it in 

 several localities in the Hebrides. Mr. Alder remarks that 

 Oban specimens are broader than usual posteriorly, and 

 have a greenish epidermis. 



It is a well-known inhabitant of the banks of Newfound- 

 land, and, in Europe, of the Norwegian seas. 



C. COSTULATA, RisSO. 



Oblong, marbled with livid zigzag lines, with radiating 

 grooves at each end ; anterior extremity very narrow, distinctly 

 projecting beyond the umbones. 



Plate XLV. fig. 1. 



Modiola costulata, Risso, Hist. Nat. PEurope Mend. vol. iv. p. 324, f. 1G5 (fide 

 Philippi — badly fig. and deser.). —Jeffreys, Annals Nat. 

 Hist. vol. xix. p. 313. — Philippi, En. Moll. Sicilian vol. 

 ii. (not vol. i.) p. 50, pi. 15, f. 10 (not of D'Orbigny 

 Moll. Canarr. nor Hani. Recent Shells, vol. i. p. 240). 



This very beautiful shell, whose existence in our seas 

 was first indicated by Mr. Jeffreys in the nineteenth vo- 

 lume of the " Annals of Natural History,'' 1 but of which 

 no description has hitherto been published in any English 

 work, might, at first sight, be passed over as either 

 marmorata or discors, to both which species it bears 

 considerable resemblance, uniting the general shape and 

 characters of the latter to the marbled painting' of the for- 

 mer. Its form is mure elongated than that of either, 



