PURPURIFERA. MOLLUSCA. BUCCINUM. 305 



gradually tapering ; on the lower one, a flattish rib or keel com- 

 mences at the junction of the lip, and, revolving, terminates about 

 the lower third of the lip; suture deep and undulating ; aperture 

 less than one half the length of the shell, rounded ; outer lip white, 

 rather thick, and spreading, with a wave at its posterior portion ; 

 inner margin nearly destitute of callus ; throat livid ; canal short, 

 very slightly recurved. Length 2 inches, breadth 1 T 1 T inch, diver- 

 gence 42. 



Inhabits the Bank fishing-grounds. 



Distinguished from B. unddtum by its more slender form, greater 

 polish, its rounded aperture, and spreading lip, and by the ribs encir- 

 cling the larger whorl. None of the specimens exhibit more than one 

 well-developed rib, and some of them are destitute of any. It has also 

 a more elongated, and more acute spire, than B. glaciale, and Mr. 

 Gray seems to have done well in separating it from that species, as it 

 is commonly received. I have seen a few perfect specimens taken 

 from fishes, which correspond accurately with Donovan's figure. 



BU'CCINUM UNDA'TUM. 



Shell ovate-conical, ventricose,with broad folds and coarse, re- 

 volving lines ; whorls six, convex ; epidermis grayish ; aperture 

 yellowish, lip slightly notched ; pillar twisted, canal a mere notch. 



State Coll., No. 9. Soc. Cab., No. 511. 



Buccinum crassum rufescens, LISTER ; Conrk., t. 962, f. 14. 



Buccinum undatum, LIN.; Fauna Suec. No. 2163. Syst. JVo/., No. 475. 



GMELIN; 3492. KNORR ; Vcrgn., iv. t. 19, f. 1. MARTINI; Conch., iv. t. 126, 



f. 1206 to 1209. PENNANT ; Brit. ZooL, t. 73. f. 9. HUTCH.; Dorset Catal., 42, 



1. 17, f. 6. MONTAGU ; Test. Brit., 237. KIENER; Iconog., pi. 2, f. 5. DRDMMOND ; 



Letters to a Young Naturalist. BLAINV. ; Malacol., pi. 22, f. 4. SOWERBT; 



Conch. Man., f. 421. DONOVAN; Brit. Shells, iii. 104. WOOD; Index, pi. 23, 



f. 107. BRUG. ; Encyc. Meth., 399, f. 1. 

 Buccinum vulgare, DA COSTA ; Brit. Conch., 122, t. 6, f. 6. 

 Tritonium undatum, MULLER; ZooL Dan., ii. 12, t. 50. FABR. ; Fauna Grcenl., 



394. 

 Buccinum striatum, PENNANT ; Brit. Zoo/., t. 74, f. 91. LISTER; Conch., t. 962, f. 



15. An. AngL, t. 3, f. 3. 



Shell thick, ovate-conic, ventricose, grayish or brownish-white, 

 encircled with prominent, raised lines, from one fifth, to one 

 39 



