Fam. 49.] NATURAL HISTORY SOCIETY. 131 



slightly reflected over the minute, perforated umbilicus ; on the 

 inner lip, the adult shell has 3 white folds or teeth, the lower 

 one formed by the turning of the lip within the aperture, the 

 second one thin, transverse and prominent, the third minute. 

 Dark horn color, the suture narrowly banded with red. Animal 

 light drab, head and tentacles darker ; foot ^ as long and wide 

 as the shell. L. 8 ; D. SJ ; An. 40; Wh. 7-8; Ap. J.— Whole 

 coast; common on wood and stones between tides. 

 2. Melampus, Montf. 

 Shell suboval, solid ; spire rather short ; aperture long and 

 narrow ; columella with several plications ; outer lip internally 

 plicate. 



1. Melampus Uneatus, Say. (Figs. 46 to 48). Shell imperforate, 

 elliptically obovate, rather thin, shining when perfect, usually 

 much eroded ; spire short, obtuse ; surface longitudinally wrin- 

 kled, and marked with minute revolving lines ; upper whorls 

 flattened , aperture long, narrow, slowly widening below ; lip 

 thin and sharp; inner lip covered with a thin, shining enamel, 

 and furnished with two fold-like teeth ; within the outer lip there 

 are usually 1-4 ridges not reaching to the edge. Horn color, or 

 brownish, sometimes with reddish revolving bands. Animal 

 reddish-brown above, paler below ; foot as long and wide as the 

 shell. L. 11; D. 6; An. 80°; Wh. 5-6; Ap. f.— Whole coast. 

 Common on marshes sometimes overflowed by the tide. 



2. Melampus bideatatus, Mont. May possibly be found on 

 the coast. It is a smaller shell with the aperture much shorter 

 in proportion and the spire more acute. L. 7 ; D. 3 ; An. 40° ; 

 Wh. 6; Ap. I. 



Order CTENOBRANCHIATA. 



Mollusks with comb-form branchiae ; that is, composed of leaf- 

 lets arranged like the teeth of a comb, and situated in a cavity 

 having an external opening upon the side of the neck. Sexes 

 in difl'erent individuals (dioecious). Shell spiral. 

 Family 49. TEREBRID/E. 

 Represented only by the genus : — 



1. Terebra, Brug. 

 Shell long, narrow, many-whorled ; aperture deeply notched in 

 front, and no true columellar plaits ; operculum annular, horny, 



