DIMYARIA. 153 



slightly gaping at the sides ; each valve with a single primary 

 tooth, sometimes in one valve only; ligament external, 

 attached to callosities at the hinge, and without the irregu- 

 lar plait of Tellina. They appear like degenerated Psam- 

 mobiae. 



Psammotcca violacea The Variegated Psammot^a. 



Plate XVII. fig. 13. Transverse, ovate-oblong, sub-ve7itri- 

 cose; radiated with purple; transversely striated. Two 

 inches broad. Inhabits the Australian seas. 



Ge«MS 40.— PSAMMOBIA.— Zeac//. 



Generic Character — Transverse, elliptical, or oblong- 

 ovate, flattened, slightly gaping at one side ; beaks promi- 

 nent ; two primary teeth in the left valve, and one in the 

 right. 



Resembling Tellina in form, but slightly gaping at the sides, and de- 

 void of the irregular plait on the anterior part. 



Psammohia Ferroensis. — The Faroe Psammobia. Plate 

 XVII. fig. 12. Oblong-oval; white, radiated with crimson; 

 finely striated transversely; valves obliquely truncate. One 

 inch and a half broad. Inhabits the European seas. 



Genus4l.—SA'^G\JmOLA.RlA.— Lamarck. 



Generic Character Transverse, somewhat elliptical, 



slightly gaping at the lateral extremities; upper margin 

 arched, and not parallel to the inferior one; hinge with two 

 approximate teeth in each valve. 



At once distinguished from the Solenes, by their never being of a 

 transverse oblong shape, nor with tlie edge of tlie valves parallel to 

 tlie base. 



Sanguinolarla rosea. — The Roseate Sanguinolaria. 

 Plate XVII. fig. 15. Semi-orbicular, smooth, shining, and 

 convex ; of a beautiful rose-colour towards the umbones, 

 which becomes gradually paler as it descends ; with acute 

 transverse striae. One inch and a half broad Inhabits the 

 sea at Jamaica. 



