32 6 POLYZOA INFITNDIBULATA. 



subcircular form, about an iDch in diameter, with an iinfinislied 

 cellular margin : cells compact, contiguous, of the size of those of 

 Lep. unicornis, horizontal, ovate, with rather thick roughish or 

 squammulose silvered walls, and a small unarmed aperture which is 

 sometimes labiate, having the inferior margin turned up a little, but 

 in the cells at the circumference the shape is circular, with an even 

 upper rim. There is an obtuse knob on the back, and near the 

 middle of it, very often, a small perforation. The central cells are 

 more or less immersed and coalescent ; those near the margin are 

 distinctly defined ; and the space between them has often an areo- 

 lated appearance, leading to the belief that it might ultimately be- 

 come punctured or fissured as in Lep, variolosa. The species is 

 indeed nearly allied to the latter ; and the most distinguishing cha- 

 racter may be the purple colour of the crust, which is quite peculiar 

 to Lep. violacea. 



37. L. BispiNosA, cells distinct, ovato-ventricose, frosted ; the 

 aperture suhquadrangular, uneven^ armed with a strong mucro 

 projecting from the centre of the upper lip, and with two long 

 cylindrical spines originating from the angles of the lower lip. 



Plate LVIL Fig. 10. 



Hah. On Modiola vulgaris from Berwick Bay. 



This species has a very close resemblance to Cellepora pumicosa 

 in its crustaceous or primary state. It is of a white colour, rough- 

 ish, with distinct cells, arranged, as usual, in semialternating rows 

 and rising towards the distal extremity. The cells are ovate with 

 glistening or silvery frosted walls ; the aperture quadrangular, un- 

 even, armed with a stout mucro projecting from the upper lip, and 

 with two very long cylindrical spines which originate from the 

 angles of the lower lip. The rim of the aperture is opaque and 

 smooth. 



The labial mucro varies in length, as does also the degree of 

 unevenness of the sides. The infra-labial spines are seldom to be 

 seen excepting on the new or marginal cells. 



Extensive as this list of Lepraliaj is, I have some specimens which 

 I cannot refer confidently to any of the species desci'ibed. When a 

 more precise knowledge of it has been acquired, a subdivision of the 



