PLATE III. 



Transparent Patella. Br. ZooL 4. No. 150. tab. 90. fig. 150. 

 Patella L^vis. Smooth Patella. Br.Zool. No. \5\. zn old shell. 

 Patella Caeruleata. Blue rayed. Da Costa. Br. Conch. 7. 4. tab. 1. 



fig. 5. 6. 



Lepas d'eau douce demi-ovoide transparent, a trols lignes bleues. 



D'Avilay tab. 1. p. 428. No. 962. 



In the young state, this shell is very transparent and horny, the 

 aperture ovoid, and the margins smooth and level ; it has also seve- 

 ral longitudinal lines of bright blue colour, which extend from the 

 vertex down the back to the margin. According to Linnsus, these 

 should be four in number ; some authors say five, and Borlase men- 

 tions nine. The blue colour is disposed in spots in some specimens ; 

 in others In lines ; and again in some others in short and interrupted 

 dashes. LinnjEus observes that the bright blue colour has not been 

 found in any Shell except this. 



The old shells are very different from the young ones, and have 

 been mistaken by some Authors for distinct species. The young shell 

 is remarkable for its pellucidity. The old ones are thicker and larger : 

 the aperture irregular : the vertex two-thirds of the shell ; and tlie 

 rays of blue, dusky. Fig. I. * represents the natural size. 



The Shell is found on the coast of Cornwall, and on the Dorset 

 coast, near Weymouth. Martin, Sibbald, and Wallace, received it 

 from the western isles of Scotland and the Orkneys. 



