30 AMERICAN MARINE CONCIIOLOGY. 



Ciirinatcd, plicated ; longitudinal folds tliirtecn to eighteen in 

 miinlKU', nioi-c or less oljliqiie, variable in number and prominence, 

 l)iit never entirely obsolete at the suture. Primary spiral ridges 

 narrow and distant, about thirty in number on the lower whorl, 

 but somewhat variable in strength and distance; sometimes 

 double or divided in two by a groove. Secondary ridges alter- 

 nate with the i)rimaries singly or by groups of two, three, or four; 

 they are distinguished from the primaries by being less prominent, 

 and occupying the depressions constituting the primary grooves. 

 In some specimens the primary and secondary ridges and grooves 

 can scarcely be distinguished from each other. Aperture ellii)tical, 

 elongated and narrow, a little more than half the length of the 

 shell, not patulous, but somewhat canaliculated and projecting 

 below; outer lip scarcely at all sinuated. Columella with a dis- 

 tinct tooth or projection near its anterior or lower extremity. 

 This projection corresponds to the second fold of the columella 

 seen in several species, such as B. lenue and 1>. itndalum, but it 

 is more tooth-like than in any other species of the genus, and 

 constitutes an important and easily recognized specific character. 

 Periostraca ciliated. 



Length 3S, diam. 20 mill. 



This is not the eilialum of Gould's " Invertebrata of Massa- 

 chusetts." That species is B. Humphrey i^ianum^ Bennett. 



Nova Scotia, Neicfoundland Bunks, northwards. 



3. B. UNRULATUM, Moller. Fig. 45. 



Kroyer's Tidsskrift, iv. 84. 1843. 



Stinipson, Review of Bucchium. 18G5. 

 Burcinum uiuhituin,, Gould (not Linn.), Invert. Mass. 305. 1841. 

 Tritomum undulatwn, Morch, Rink's Greenland. 84. 1857. 

 Bucdnum Lahradorense, Reeve, Conch. Icon., f. 5. 1846. 



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

 encircled b}'^ prominent primary raised lines and minute inter- 

 vening secondary stri;e; with twelve or thirteen longitudinal, 

 obliquely waved, elevated ribs or plaits on the spire and upper 

 portion of the body-whorl; epidermis velvety, 3'ellowish-brown ; 

 whorls six, regularly convex; aperture oval, about one-half the 

 length of the shell, golden yellow Avithin ; minute striai extend 

 some distance within the mouth and produce faint crenulations of 

 the outer lip; this is somewhat everted and arched so as often to 

 produce a conspicuous notch at about its posterior third ; coin- 



