280 TROCHID^. 



not larger than those on the base of our shell, while its base is 

 nearly smooth ; its umbilicus is much smaller. In color, size, and 

 general shape, the shells are alike. 



Margarita minutissima. 



Shell very minute, sub-ovately globose ; whorls three, convex, longitudinally 

 furrowed; spii-e short, obtuse; suture strongly imjiressed; a])erture orbicular, 

 umbilicus large, deep. 



Mcmjarita miiitilissimd, Mighels, Bost. Journ. iv. 349, pi. 16, tig. 5 (1843). — Stimp- 

 soN, Check Lists, 4. 



Shell very minute, sub-discoidal, globular-ovate, of a dull ash 

 color ; whorls llirce, convex, with distinct longitudinal, approximate 

 sulci, running obliquely, and disappearing as they ap- 

 proach the umbilical region ; spire very low and obtuse 

 I at the apex ; sutui-e deep, a])crture circular ; lip sharp 

 and nearly continuous posteriorly ; umbilicus large and 

 M.7nniut,ssu,m. jj^q^q^^j^j^ Length, about one fifth of an inch; breadth, 



about equal to the length. 



Casco Bay. 



I have never found but a single specimen of this shell, which I 

 took from the stomach of a haddock. It is not very nearly allied 

 to any of the other s]jecies found on tlie coast. Under a magnifier, 

 it somewhat resemljles M. varicosa, Nob., in tlie ultimate Avhorl. 

 It is, however, readily distinguished by its very depressed and ob^ 

 tuse spire (^Mighels^ . 



Margarita undulata. 



Fig. 172*. 



Shell orbicular, low-conical, dark flesh-color, encircled with regularly disposed 

 spiral lines, alternately larger and smaller, coarsely plaited at the sutures. 



Margnrita umluhtta, Sowerby, Malacol. and Conchol. Mag. i. 20; Coiuhol Ilhist. {Mar- 

 garita), fig. 4. — Gould, Inv. 1st cd. 254, fig. 172*. -De Kay, N. Y. Moll. 109.— 

 Stimpson, Check Lists, 4. 



Margariia strintn, vnr. Grm)l<tndica, Moller, Ind. Moll. Gr. 



Tiirho incarniitiis, CoriTiiouY, Bost. Journ. Nat. Hist. ii. 98, pi. 3, fig. 13. 



Trvchus tumiJus, Mont.\gu, Leth. Suev. pi. 30, fig. 3. 



Shell thin, orliicular, depressed-conical, usually of a bright brown- 

 ish-red color; sometimes rose-red, at others pale flesh-colored ; whorls 

 four, convex, somewhat flattened above, undulated near the suture 

 .by short folds or wrinkles, and encircled by numerous, elevated, 



