104 Rev. T. HiDcks on Polyzoa 



[Spitzbergen (Swedish Expedition).] 



Zoooecia ovate, moderately convex, strongly reticulate-punc- 

 tate ; orifice suborbicular, somewhat compressed, with a 

 broad well-marked sinus on the inferior margin ; peristome 

 not raised ; no central tooth ; avicularium large, elongate- 

 oval, sometimes half immersed, sometimes prominent, placed 

 in the centre immediately below the mouth, occasionally at a 

 short distance beneath it or turned transversely. Oooeciiim 

 rounded, closely adnate above, thickly punctured ; peristome 

 in the fertile cells not raised. 



This is another form belonging to the same group as the two 

 preceding. It is figured by Smitt, and described by him as 

 Escharella port f era, forma edentata. It is distinguished from 

 that species by its reticulate and coarsely punctured surface, 

 by the form of the mouth, which is much less arched above 

 (compressed) and with a more marked sinus below, and by 

 the large elongate-oval avicularium, which is somewhat 

 variable in position, whereas that of L. porifera is constantly 

 attached to the inferior margin. The two also differ much in 

 general aspect. 



The preceding three forms occur amongst Eeikiavik dredg- 

 ings only in an incrusting state ; and there is nothing to show 

 whether they ever assume the Escharine mode of growth. 



18. Lepralia radiatula, n. sp. (PI. X. figs. 9-14.) 

 ? Celhpora plicata, var., Smitt, Forteckn. iv. pi. xxviii. fig. 193. 



Zoooecia ovate, disposed in linear series, whitish, minutely 

 roughened, traversed by rib-like lines, which run from the 

 margin towards the centre ; mouth suborbicular, surrounded 

 by a thin, much-raised, frill-like peristome, wdiich is cleft in 

 front into a deep loop-like sinus ; within it on one side a small 

 avicularium, the mandible directed upwards ; a minute pointed 

 denticle immediately within the lower margin. Oooecium 

 semicircular, punctured, set far back. The peristome frequently 

 rises at the sides into prominent expansions, w^hich are curiously 

 cut and crenated at the top, and present a very fantastic ap- 

 pearance. 



On shell, zoophytes, &c., common. 



I have met with no description of this remarkable form ; 

 but it seems to be represented in Smitt's figure 193 (Forteckn. 

 part iv.). He refers it to his Cellepora plicata, with which, 

 I confess, I cannot see that it has any close affinity whatever. 

 It varies much in different states of growth, and especially in 

 the degree in which the peristome is developed : at times it 

 forms a plain border round the mouth (PI. X. fig. 10) ; at 



