ASTRALIUM. 231 



Synonyms: Stella (Klein) H. and A. Adams, 1858, (type, A. 

 asteriscns Rve.), Calcar Montfort, 1810, (type, A. calcar Linn. ?) 

 and Carinidea Tenison-Woods, not Swainson. 



There has been considerable diversity of opinion regarding the 

 group above defined, both as to its contents and its proper designa- 

 tion. Stella was the first name proposed for it ; but since the no- 

 menclature (almost) universally adopted by zoologists dates from 

 the publication of the tenth edition of Linmeus (1758), we are com- 

 pelled to reject the names proposed by Klein in 1753. This course 

 is rendered the more imperative by the nature of Klein's work ; for 

 his " genei-a " are as often denominated by a phrase as by a single 

 word. Calcar of Montfort was probably founded on a species of 

 this subgenus. But this is very uncertain, as his figure might be- 

 long to any one of several very different forms. (See also Fischer, 

 3fan. de Conch., p. 813.) As to Carinidea Swains., which Tenison- 

 Woods has supposed to include the group of A. Jimbriatum, A. ten- 

 toriiforme etc., there is no warrant for using it in any such sense; 

 for Swainson's two types are (1) an umhilicated species of Trochus, 

 and (2) a species of Uvanilla, (A. buscJiii Phil.). Hercoles Montf. 

 referred to this group by some authors, is not a mollusc. As to the 

 limits and contents of Cyclocantlia, as here defined, I am aware that 

 there is room for controversy. Fischer and others have distributed 

 a portion of the species among several adjacent subgenera. I have 

 included with considerable hesitation A. fimbrlatum and A. tentorii- 

 forme.; but I do not think that they would be any better placed 

 with ^4. olivaeeus etc. in Uvanilla. 



It is very difficult to express in a diagnosis the differences be- 

 tween the shells of this group and of Astralium, .s. s. Both contain 

 flattened wheel-shaped umbilicate forms, with long peri2:)heral 

 spines, and both have com]:)act trochiform species. The two groups 

 occupy almost opposite areas upon the globe. 



A. CALCAR Linn., 1758. PI. 52, figs. 27, 29, 30 ; PL 56, fig. 74. 



Shell conoid, more or less depressed at ajiex ; grayish greenish, 

 or brownish cinereous ; whorls 6, flattened above, and radiately pli- 

 cate, the folds rather unequal and irregular ; periphery carinated 

 spinose, bearing about twelve radiating more or less foliated spines 

 upon the body-whorl ; last whorl deeply descending toward the 

 aperture ; base convex, concentrically more or less densely squa- 

 mosely lirate, the outer lirae generally prominent and subspinose, 

 sometimes causing the periphery to appear bicarinate ; ajjerture 



