61 



Figures. 



Lima inflata. PI. N. Pig. 1. Shell, containing the animal with its ten- 

 tacular fringe and byssus-spinning foot. 



Lima squamosa. PL 28. Pig. 163. Shell, showing its white substance and 

 scaly sculpture, with the byssus protruding from the anterior gape. 



Genus 7. PEDUM, Bruguiere. 



Animal; oval-oblong, fat, lobes of the mantle free, thickened at 

 the edge, and furnished with several rows of tentacular cirrhi 

 and equidistant smooth tubercles; a pair of large branchice de- 

 scending on each side ; foot worm-shaped, furnished tvilh a large 

 silky byssus ; mouth oval, having on each side a pair of labial 

 palps. CQuoy and Gaimard.J 



Shell ; inequivalve, thin, compressed, slightly auriculated, loiver 

 valve rather convex, refected at the sides, deeply sinuated near 

 the hinge, lower valve flat ; hinge toothless, with the ligament 

 partially external, contained ivithin a channelled pit running 

 across a produced umbonal area of the loiver valve. 



The earliest publication of the very remarkable shell which constitutes 

 this genus was the mention of " a rare oyster from the Indies " more than 

 a century ago in the ' Catalogue Raisonne ' of Davila ; and no other spe- 

 cies has been met with. Prom having a largely-developed umbonal area, 

 it was then called the ' Spondylus-like Oyster/ but, unlike that genus, it 

 has a very conspicuous sinus for the passage of a stout silken byssus, and 

 according to the observations of MM. Quoy and Gaimard, partakes much 

 of the character of the Pectens. 



Until lately the Pedum, reported to be an inhabitant of the Mauritius, 

 has been a shell of great rarity ; but it has been found in comparative 

 abundance in the Eed Sea imbedded chiefly in masses of madrepore, and 

 the accomplished naturalists of the Astrolabe have gone so far as to ex- 

 press their belief that the animal has the power of boring and enlarging its 

 place of habitation. 



Figure. 



Pedum Spondyloideum. PI. 28. Pig. 164. Shell, showing its reflected 

 sides and umbonal area. PI. N. Pig. 3 : showing a mass of madre- 

 pore with four specimens imbedded therein. 



