PORELLA L^VIS. 335 



t of a very fine specimen from Shetland 1 inch, 

 breadth 1 inch. 



HABITAT. On corals &c., chiefly in very deep water. 



LOCALITIES. Shetland (Fleming and Barlee) : 20-25 

 miles N. and N.N.E. of Unst, in 100-170 fathoms (A. 

 M. N.). 



GEOGRAPHICAL DISTRIBUTION. West and north coasts of 

 Norway, tolerably abundant, 30-150 fathoms, often on 

 Ocuiina prolifera (Sars) : " extra Norvegiam Oculitue 

 affixam ex abysso," 200-300 fathoms (Baron Uggla) : 

 Greenland, a specimen in the Copenhagen Museum (teste 

 Smitt) : Nova Zembla, Matotschkin-scharr, in Beluscha 

 Bay, 30-70 fathoms; Kara Sea (Stuxberg and Theel). 



When finely developed, P. l&vis has a rather broad 

 shrubby growth, the principal shoots, which are much elon- 

 gated, dividing into very numerous dichotomous branch- 

 lets. One of its most striking characteristics is the smooth 

 and polished surface, which extends over the whole of the 

 lower part of the zoarium. The cell- apertures are only 

 met with in any number on the upper portion of the 

 branches ; below they seem to be almost obliterated by a 

 varnish-like coating. The walls over the whole zoarium 

 are thick and dense, and the apertures are generally 

 deeply sunk, while in the lower part of it the calcification 

 seems to have proceeded so far as to remove all traces 

 of the cell. The zooecia are immersed, except towards the 

 extremities of the branches, where they are somewhat pro- 

 minent; the marginal punctures are hardly distinguish- 

 able in the older cells. In young cells a line of punctures 

 is sometimes present, running across the front, a little 

 below the mouth. The orifice is rather large, well arched 

 above, and contracted a little below the middle, where 



