COLUMBELLA. 357 



Columhella avara, Sat, Journ. Acad. Nat. Sc. ii. 230 (1822). — Gould, Inv. 1st cd. 313, 

 fig. 197. — Adams, Bost. Journ. Nat. Hist. ii. 363. — De Kay, N. Y. Moll. 139, pi. 

 8, fig. 179. — SowKRBY, Thes. 128, pi. 38, fig. 110. — Stimpson, Check Lists, 5. 



Shell small, ovate-conic, elevated, strong, of a light straw color, 

 finely reticulated or l)lotched with various shades of reddish-brown ; 

 surface covered with equal and regular revolving lines, in- 

 terrupted by as many as fifteen smooth, obtuse folds or ribs ^'^' ^'^' 

 running lengthwise of the shell ; and as the folds extend 

 only half the length of the lowest whorl, the remaining half 

 is marked by the revolving lines only ; whorls six, nearly 

 flat, forming an elevated, pointed spire ; suture distinct, 

 and somewhat scalloped by the folds ; aperture narrow-oval, 

 aI)out one third the length of the shell ; very little contracted by the 

 thickening of the middle of the outer lip; this lip is simple, some- 

 what thickened externally, and having a series of lengthened teeth 

 just within the margin ; inner lip invested with a plate of callus, 

 which is also toothed in a similar manner, in mature shells ; oper- 

 culum horny. Length, three fifths of an inch ; breadth, one fourth 

 of an inch ; divergence, thirty-three degrees. 



Sent me from jMartha's Vineyard l\y Dr. L. M. Yale. Professor 

 Adams says it is common at New Bedford and vicinity, also at Fal- 

 mouth and Nantucket. Cape Cod, however, seems to be its north- 

 ern limit, though a solitary, worn specimen is occasionally found 

 within the Capes. It lives below low-water mark. It is abundant 

 on the shores of the Southern States. Gull Island (Smith). 



Mr. Say referred this shell, somewhat doubtfully, to the genus 

 Colambella ; and as it still remains equivocal between Cohimbella 

 and Bucciimm, it is best to let it remain where he placed it. It 

 varies much in its length and coloring, being in general longer than 

 described by Say. It is usually covered with a dirty-brownish pig- 

 ment. The middle of the last Avhorl is frequently angular, espe- 

 cially in immature shells ; in these too, and indeed in a majority of 

 the shells I have seen, the denticulations of the aperture are want- 

 ing. There is, however, no other shell resembling it on our coast, 

 and it is easily recognized. 



Columbella rosacea. 



Fig. 19.5. 



Shell small, acutely conic, white, tinged with rose color ; whorls six, covered 

 with spiral lines ; aperture ovate, shorter than the spire, pillar arched and flat- 

 tened, lip sharp, and without teeth within. 



