from Iceland and Labrador. 107 



tion) ; Greenland (AioUer and Torell) ; Holsteinborg Har- 

 bour, 7-3.5 fatlionis ; entrance of Baffin's Bay, 175 iatlioins 

 ('X'alorous' drodt!:inj^.s) ; Anticosti and Mingan Islands; 

 South Laltrador {I^icLuird).] 



In this very distinet speeics, the small oval avicularla are 

 sometimes placed on each side of the mouth at the top, or 

 sonu'tinics on one side only: occasionally they occur about 

 the middle of the aj)criure ; they are also distributed irregu- 

 larly over the zoarium. In many cases they arc wanting 

 altogether in connexion with the mouth of the cell. 



Genus Rktepora, Imperato. 



25. Retepora Tr«?^/r///a«a, n. sp.,Busk (MS.). 

 (PI. XI. figs. 9-13.) 



Retepora ceUitlosa (Linn.), forma uotopachi/s (Busk), var. elongata, 

 Smitt, I. c. pt. iv. pp. 30 & 204, pi. xxviii. "ligs. 226-232. 



Zoarium irregular, sometimes giving off long free branches ; 

 fenestra; elongate, narrow, lozenge-shaped. Zoocecia immersed, 

 elongate, somewhat rectangular, bordered by lines, the mouth 

 suborbieular ; peristome thin, raised, the inferior margin pro- 

 jecting and with a very minute central sinus ; immediately be- 

 lowit in many of the cells a j)rominent rostrum placed oblifpiely, 

 bearing on its summit a large avicularium with strongly in- 

 curved beak and a long triangular mandible pointing down- 

 wards. Oo<vrium small, rounded, smooth ; placed very far 

 back behind the mouth and se])arated from it, in the centre of 

 the arch of the opening, a small denticle (Plate XI. fig. 12). 



This form has been very accurately described by Smitt ; 

 but he regards it as a variety of the Crag species E. nolo- 

 2)achys^ Busk. Some years since Mr. Busk, Avho had met with 

 it amongst Dr. "Wallieh's dredgings, gave it the MS. name 

 which I have retained in this paper, and which fittingly 

 commemorates one of the earliest and ablest pioneers in the 

 work of deep-sea exploration. I agree with Mr. Busk that it is 

 specifically distinet, though in some respects it seems to approach 

 the fossil form. The chief points of difference between it and 

 li. notopachys are to be found in the mouth, which in the latter, 

 according to iJusk's figure, is furnished with a rather doe})ly 

 incised sinus on the lower margin, whereas in R. WaUkhiana 

 the sinus is very minute and shallow* — and in the ovicell, 

 which in the last-named is small, with a very moderate orifice 

 and a eon.«:picuous denticle in the centre of the oral arch, while 

 that of the Crag form is described as large and open in front. 



The 'position of the ovicell in the present species is also 



• The contoiu of the oral aperture is very different in the two specie?. 



