106 UNIVALVES. MUREX. 



Erythrinus Nodulous. Samar Samar. 



Dentatus Toothed. 



DIVISION IV. SHELL TURRETED, WITH A LONGITUDINAL 



FISSURE EXTENDING FROM THE APERTURE 

 TO THE SUMMIT. 



Fissus Slit. Fissurella Fissure. 



DIVISION V. SHELL TURRETED, WITH A VERY LONG SPIRE. 



FAMILY 1. The aperture ending in a long beak, and the outer 



lip toothed. 

 Fusus Spindle. Unicornis Unicorn. 



FAMILY 2. Without the beak, and the aperture not toothed. 

 Tuberculatus Tuberculated. Auritus Eared. 

 Palustris Marsh. Lividus Livid. 



Ater Black. *Costatus Ribbed. 



DIVISION VI. SHELL OBOVATE, WITH TRANSVERSE NODU- 

 LOUS BELTS, PILLAR-LIP GRANULATED, AND THE OUTER 

 LIP THICKENED AND TOOTHED WITHIN. 



Onlscus Wood-louse. 



MUREX. ROCK OR TRUMPET-SHELL. 



Animal a Limax: Shell univalve, spiral, rough, with 

 membranaceous sutures; aperture oval, ending in an en- 

 tire, straight, or slightly ascending canal. 

 THE most prominent character which distinguishes the 

 one hundred and seventy-two species of the Murex from 

 those of the two preceding genera, consists in the beak, 

 which inclines neither to the right nor left, but is almost 

 invariably straight and very much produced, sometimes 

 turning a little upwards. 



