296 MARGARITA. 



M. (?) NUDIUSCULA Martens. Unfigured. 



Shell perforated, conical, bicarinate, pearly ; whorls 4J, gradate, 

 the first 2 yellowish, smooth, the following ones denuded-pearly, 

 beneath the suture sculptured with a series of nodules and smooth 

 spiral lirse, few in number or evanescent; last whorl with elevated 

 concentric lines on the base, stronger on the periphery, and radiat- 

 ing impressed lines. Aperture rhomboid-rounded ; columellar 

 margin concave, thickened, below a little expanded, edentulous. 



Alt. 4, diam. 4 mill. ; apert., alt. 2, diam. 2? mill. (Martens.) 



East Coast of Patagonia, 43 S. lat. ; 60 frns. depth. 



Trochus (Margarita) nudiusculus, MARTENS, in Sitzungsberichte 

 Ges. Naturforsch. Freunde, Berlin, 1881, p. 77. 



Reminds one most of Tr. nudus Phil., but is different in the 

 sculpture and the open, though very narrow, umbilicus. (Martens.) 



M. CANFIELDI Dall. 



Shell of seven whorls, the last whcrl comprising more than half the 

 shell. Above, sutures small but deeply channelled ; whorls smooth, 

 with three revolving ribs close to the suture, also three or four on the 

 lower part of the whorl. Color pearly, with bronze-yellow pencil- 

 lings obliquely to the suture. Surface of the whorls rather flattened, 

 semicarinated, convex. Shell umbilicated with nine basal revolving 

 ribs. Umbilicus strongly carinate internally, smooth, narrow and 

 small. Aperture rhomboidal, pearly, with grooves answering to the 

 exterior ribs. Columella straight, with a slight callosity, but not 

 reflected. (Dall.) Alt. *4; min. diam. '3, maj. diam. *4 in. 



Monterey, California. 



Gibbula canfieldi DALL, Am. Jourft. Conch, vii, p. 129, 1871. 

 (/ Calliostoma Canfieldi Dall, MSS., 1866.) 

 I have not seen this form. 



M. LTRULATA Carpenter. PL 65, figs. 81, 82, 87. 



Shell umbilicate, globose-conical, solid, lusterless or slightly shin- 

 ing, purplish, unicolored, or with large radiating white patches 

 above, or around the periphery, or spiral darker lines, or spiral 

 articulated lines. Surface either with (1st) a few (2-4) strong lirse 

 above, their interspaces smooth, the base with about 8 concentric 

 liruhe, or (2d) more numerous narrow irregular lirulse above, those of 



