No. 9. DONAX. 



Wedge Shell. 



Inhabitant a Tethys. 



The shell bivalve, with the margin generally crenulated, the anterior end 

 very obtuse, hinge with two teeth, a solitary one somewhat remote, (the lat- 

 ter rarely double, triple on none.) According to Grewelin, this genus has 

 19 species. Aova£ signifies an arrow: on account of the rapidity of its 

 darting through the sand, this term might have been invented. 



It is generally found in the sand on the sea shores, when left dry by the 

 reflux of the tide. The prevailing color is a fine rich purple, but many species 

 are of a fine rich olive yellow cast. The Donax may probably derive its 

 name from its shape, which resembles the head of a javelin or arrow; or its 

 activity on the approach of danger, its arrowy shell being well calculated for 

 penetrating quickly the yielding substance of the shore. 



The Donax presents so great a diversity in external character that it has 

 occasioned the genus to be separated into five divisions. 



DIVISION I. With decussated and muricated stria. 



Scientific name. 



Scortum, 



Pubescens, 



Rugosa, 



Locality. 

 Ceylon, East Indies. 

 Amboyna. 



Scientific name. 

 Muricata, 

 Spinosa, 



Locality. 

 Indian Ocean. 

 Tranquebar. 



DIVISION II. Longitudinally striated. 



Serra, 

 Trunculus, 



So. Sea, Mediterranean, 

 Mouth of the Niger. 



Tranquebar, C. G. Hope. 



G. Britain, Med. Sea, 

 West Indies. 



Striata, 

 Denticulata, 

 Incarnata, 

 Elongata, 



Jamaica, Mediterranean. 

 Med., Africa, G. Britain. 

 Tranquebar. 

 Red Sea. 



Plebeia, 

 Castanea, 

 Faba, 

 Straminea, 



DIVISION III. Transversely striated. 



Dorsetshire, E. 

 West of England. 

 Malabar. 



Candida, Tranquebar. 



Radiata, do. 



Cuneata, do. E. Indies. 



Madagascarensis, Madagascar. 



