26 . Rev. T. Hincks 07i the 



[Spitzbergen, Greenland, 100 fms., Godhavn Harbour, 

 Disco.] 



The form which I refer to Smitt's Cellepora plicata differs 

 slightly from the description and figures given by that author ; 

 but in essential particulars, I believe, it agrees with them. 

 In the specimens from the Queen Charlotte Islands the avicu- 

 larium is well within the peristome, and there is little if any 

 trace of the umbo, on which, according to Smitt, it is placed 

 in his C. plicata. This, however, may be due to the greater 

 development of the peristome, by which the umbo may have 

 been to a large extent concealed. The cells are often in- 

 vested by a membranous epitheca. 



Smittia spathulifera, n. sp. (PI. IV. fig. 3.) 



Zooecia large, ovate, quincuncially arranged, very mode- 

 rately convex, bordered by delicate raised lines ; surface 

 covered with rather large round punctures, which, however, 

 are in great measure concealed by the stout epitheca that 

 clothes tlie zoarium ; orifice arched above, lower margin 

 straight and within it a large bifid tooth ; peristome much 

 raised (especially above) forming an elongate secondary orifice, 

 produced below into a spout-like sinus, which is occupied by 

 a spatulate avicidarium ; mandible directed downwards. 

 Ooecium large, immersed, closely united to the cell above ; 

 surface roughened, punctured round the edge. Zoarium 

 forming a brownish crust. 



Houstou-Stewart Channel. 



MuCEONELLA, Hincks. 

 Mucronella ventricosa, Hassall. 



Virago Sound, in about 20 fms., on shells. 

 [Britain, France (S.W.), Mediterranean, New Zealand, 

 Bergen, Greenland, Nova Zembla, Kara Sea.] 



Mucronella pavonella, Alder. 



Virago Sound. 



[St. Lawrence, Greenland, Nova Zembla, Spitzbergen, Fin- 

 mark, off Jutland, Britain (north-east) .] 



Mucronella prcelucida^ n. sp. (PL IV. fig. 1.) 



Zooecia large, ovate, quincuncial, slightly convex, separated 

 by raised lines ; surface thickly covered with roundish punc- 

 tures, lustrous ; orifice arched above, lower margin straight 



