SMITH: DESCRIPTION OF NEW SPONDYLUS AND HELIX. ?! 



Longit. circa 12^ inillim., alt. ah. apice valvce dextrce ad mar- 

 ginem ventralem i^o mill., valvce sinistne IJO ; diain. 

 go mill. 



Hab. : Madeira, at a depth of four fathoms (Poivell) ; Porto 

 Grande, San Vincent, Cape Verde Islands, in Brit. Mus., 

 collected by J. Macgillivray during the voyage of H.M.S. 

 Herald. 



This is a very solid ponderous species, remarkable for the 



brightly coloured border within the valves and the character of 



the sculpture. This consists in the left or upper valve of about 



eleven radiating sub-equidistant ribs, which bear numerous very 



short blunted spines. The spaces between these principal 



ribs are divided by very narrow radiating sulci into five or six 



less pronounced ribs, which, at their terminations, form notches 



at the margin. In addition to these ribs the entire surface, 



when not overgrown or abraded, exhibits a very minute 



sculpture consisting of extremely fine and minutely prickly or 



squamate radiating lirae, crossed by fine wavy lines of growth. 



The right or attached valve appears to be more equally and 



more strongly ribbed than the other. The ribs are finer at the 



sides towards the auricles, and rather stronger towards the 



posterior lower part than in front, the crenulation of the margin 



varying in coarseness accordingly. The ligamental area of the 



right valve is large, as usual in most species, curves slightly 



backwards, is nearly equilaterally triangular, the groove being 



only visible near the apex. The interior of the valves between 



the pallial line and the purple, coral-red, or deep rose border, 



is white, the rest of the surface enclosed by the pallial line is 



dirty whitish, and more or less stained with patches of a 



greenish or livid tint. The strong hinge-teeth in the left or 



upper valve are stained with brown, and also the dentiform 



projections on each side in the other valve. The two central 



teeth in this valve, between which the ligament rests, are 



generally white. The inner margin of the valves on each side 



at, and a little below, the auricles is very finely crenulated, and 



all round the ventral part it is more coarsely denticulate. The 



