BIVALVES. — VENUS. 49 



of no great variety; they are usually found buried in the 

 sand. It is not exactly ascertained whether any of this 

 genus are natives of rivers. 



The Donax derives its name from its shape, which re- 

 sembles the barbed head of a javelin or dart. 



DO^ AX— Wedge-shell. 

 Division I. — With decussated and muricated strice. 

 Scortum — Beaked. Muricata — Prickly. 



Pubescens — Spiny. Spinosa — Spinous. 



Division II. — Longitudinally striated. 

 Rugosa — Wrinkled. Striata — Striated. 



Serra — Crenated. Denticulata — Toothed. 



*Trunculus — Common. Incarnata — Flesh-coloured. 



Elongata — Elongated. 



Division III. — Transversely striated. 

 Plebeia — Horn-coloured. Candida — White. 



*Castanea — Chesnut. Radiata — Radiated. 



Faba — Bean-shaped. Cuneata — Wedge. 



Straminea — Straw-coloured. Madagascariensis-7V/ac?a^ascar. 



Division IV. — Smooth. 

 Complanata — Single-rayed. Scripta — Lettered. 



Laevigata — Smooth. Stultorum — Foolish. 



Division V. — Shell with transverse membranaceous ridges. 

 *Irus — Ragged. 



VENUS.— Venus. 



Animal — aTethys: Shell bivalve, the frontal margin flat- 

 tened, with incumbent lips; hinge with three teeth, all of 

 them approximate, the lateral ones divergent at the tip. 

 IT has already been observed, that this genus, with re- 

 gard to beauty, bears a decided pre-eminence over all the 



D 



