PURPURIFERA. MOLLUSCA. BIJCCINUM. 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 ly^ inch, diver- 

 gence 42^. 



Inhabits the Bank fishing-grounds. 



Distinguished from B. undatum 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. glacidle, 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 UNDATUM. 



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

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

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



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



Buccinum crassum rufescens, Lister ; Conch., t. 962, f. 14. 



Buccinum undatum. Lin. ; Fauna Suec. No. 2163. Syst. J^at., No. 475. 



Gmelin; 3492 Knorr ; Fcrgn.,\v. t. 19, f. 1. Martini; Conch,,iv.t. 126, 



f. 1206 to 1209. Pennant ; Brit. Zool., t. 73. f. 9. Hutch.; Dorset CataL, 42, 



t.l7,f.6. Montagu; Test. Bril.,2'37. Kieskk; Iconog.,p\. 2, f. 5. Drummond ; 



Letters to a Young Naturalist. Blainv. ; Maiacol., pi. 22, f. 4. Sowerby; 



Cunch. Man., f. i2l. Donovan; Brit. Shells, iii. 104. Wood; Index, pi. 23, 



f. 107. Brug. ; Encyc. M6th., 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 Granl., 



394. 

 Buccinum striatum. Pennant ; £ri<. Zooi., t. 74, f. 91. Lister; Conch., t. 962, f. 



15. Jin. 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 



