1 15 



shortly tubular. The margin is surrounded by numerous 

 long and slender bristles, which are very commonly destroyed 

 on all but the distal rim, and very frequently are wholly 

 destroyed, from being so brittle ; they may however generally 

 be noticed as fragmentary tubercles. This species ap- 

 proaches very closely to the L. nitida especially when the 

 bristles are destroyed. It differs however from that species, 

 in having the transv erse bands so short as to extend only one- 

 fourth of the diameter, in having the aperture circular and 

 surrounded with bristles and having the cells contracted at 

 each extremity. 



LEPRALIA COCCINEA. Encrusting, calcareous; cells 

 oval, rough, with a blunt process near the proximal lip 

 of the aperture. 



Lepralia coccinea, Johnston's Brit. Zooph., p. 278. 



Hab. On rocks near low water mark. Talland sand bay ; 

 Combe Lansallos ; Polperro ; Goran; Falmouth; Mount's 

 bay. 



This generally occurs in circular encrusting patches of 

 about one inch in diameter, but it sometimes covers a space 

 of an inch and three-quarters. It somewhat varies in colour 

 according to the locality in which it grows ; it is most com- 

 monly of a yellowish brown, or brownish flesh colour, fading 

 occasionally to a white. The cells are oval, and arranged 

 in circular rows. Their surface is rough, granular or frosted, 

 which is more apparent in dried than in living specimens. 

 The aperture is oval, plain, with a denticle near the proximal 

 margin. As the cells lie on the crust in close approxi- 

 mation and the apertures and denticles give it a waved ap- 

 pearance, the surface being granular, the line of demur- 

 cation between the cells is very obscure, hence the whole 

 seems indistinct and confused. 



L. TRIDENTATA. Encrusting, calcareous; cells oval, 

 horizontal, rough; apertures oval, with a triangular den- 

 ticle on the proximal, and one on each of the lateral 

 rims. PI. xxii. fig. 5. 



Hab. On rocks, stones, &c, from deep water to low 

 water mark. Common. 



This calcareous and encrusting species varies from one 

 quarter to one inch in diameter, in living specimens it is 

 generally of a yellowish red colour inclining to a purple, but 

 it is sometimes of a delicate flesh colour, all of which slightly 

 fade in death. The cells are oval, horizontal, and closely 

 arranged in circular rows ; th< \ ore rather indistinct at first 

 Bight from their frosted surfaces, their irregularity or waved 

 appearance about the apertures, and their being somewhat 



