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. 



DONAX Wedge-shell. 



DIVISION I. With decussated and muricated stria. 

 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, 



E longa ta Elongated. 



DIVISION III. Transversely striated. 

 Plebeia Horn-coloured. Candida White. 



*Castanea Chesnut. Radiata Radiated. 



Faba Bean-shaped. Cuneata Wedge. 



Straminea Straw-coloured. Madagascariensis-Madagascar. 



DIVISION IV. Smooth. 



Complanata Single-rayed. Scripta Lettered. 



Laevigata Smooth. Stultorum Foolish. 



DIVISION V. Shell with transverse membranaceous ridges. 

 *Irus J 



VENUS. VENUS. 



Animal aTethys: Shell bivalve, the frontal margin flat- 

 tened, with incumbent lips; hinge ibith 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 



