LEPRALIA. 325 



35. LEPRALIA IMMERSA, Dr. Johnston. 

 Hab. On shells and stones from deep water. 



The crust is rough, the aperture small, with a blunt 

 tooth on the upper lip ; the surface minutely granular. Dr. 

 Johnston says it differs from L. ciliata in having a more 

 solid texture ; in forming larger patches ; in the much less 

 distinctness of the cells; in the aperture having no rim, 

 but a slight projection in the upper margin ; and in there 

 being no knob behind it. It is not uncommon on the west 

 coast. I have specimens of it, from Tiree, on Pinna ingem. 



36. LEPRALIA VIOLACEA, Professor Forbes. 



Hab. On Nullipores, from the Isle of Man, E. Forbes j 

 coast of Cornwall, Mr. Peach ; Dr. Greville. 



" This species is nearly allied to the latter, and the most 

 distinguishing characteristic may be the purple colour of 

 the crust, which is quite peculiar to it." 



37. LEPRALIA BISPINOSA. 



Hab. On Modiola vulgaris, Berwick Bay, Dr. Johnston. 



Dr. Johnston states that this species bears a very close 

 resemblance to Cellipora pumicosa. By his figure of it 

 however (plate Ivii. fig. 10), it seems sufficiently distin- 

 guished from it by the very long spines which originate 

 from the angles of the lower lip. 



