222 



ASTRALIUM. 



Operculum (pi. oO, i^g^. 57, 58) oval, nucleus sublateral ; outside 

 white or slightly brownish, very convex, nearly smooth, excavated 

 near the center. 



Trochus orichalceus (figs. 8, 9) T. aster, and T. heliucus Phil., T. 

 planus (Gm.) Phil., Astmlium deplanatum Link and perhaps T. 

 inermis Gniel. are synonymous. 



An abundant and variable sjjecies. Figs. 1, 2, represent the typ- 

 ical form. The following variety has typically a very distinct as- 

 l)ect; but I am unable to separate it specifically by constant or 

 well marked characters. 



Var. spiNULosuM, Lam., 1822. PI. 51, figs. 4-6. 



Shell conically elevated, imperforate ; whorls flattened above, ra- 

 diately costulate or spirally lirate, or both, and tuberculate or squa- 

 mose ; peripheral carina generally subspinose or nodose ; concentric 

 lirse on the base three to six in number, the inner generally nodose. 

 Two specimens measure as follows : 



Alt. 32, diam. 61 mill ; alt. 38, diam. 45 mill. 



W. Indies; Florida. 



Fig. 6 is drawn from a specimen from Key West, Florida, collec- 

 ted by Hemphill. Lamark's T. costulatus (pi. 51, fig. 7), is in form 

 intermediate between typical longispina and var. spinulosum; it is 

 umbilicate and obliquely plicate above. I cannot tell what species 

 Reeve figured as T. spinttlosus ; it seems to be a very depressed form 

 of A. petrosum Mart. It is certainly not the spinulosum of Lamarck. 



A. ARMATUM Phil, 1848. PI. 51, figs. 10, 11. 



Shell conic, apex acute ; sculpture as in var. spjinnlosum. 



Alt. 16, diam. 27 mill. 



Antilles (Philippi); St. Croix. 



A single specimen of this form I found in a suite of yl. longispina 

 from St. Croix. From that species it diflTers in the conical acute apex. 

 A. BREVispiNA Lam., 1822. PI. 52, figs. 12, 13. 



Shell conic, imperforate, solid ; whorls 6-7, flat above, obliquely 

 costate below the sutures, then with several revolving series of gran- 

 ules; periphery sharply carinate, armed w'ith short triangular spines 

 which festoon the sutures and project more or less, about 10-13 

 in number on the last whorl ; base a little rounded, radiately lamel- 

 lose striate and concentrically lirate, the liras three to five in num- 

 ber, mostly tuberculate, especially in the young ; aperture transverse, 

 oval, channelled at outer angle ; columella short, arched ; place of 



