154 Rev. T. Hincks on the 
sinuated in front,” or, as the character is given in the diag- 
nosis, ‘slightly channelled in front.” 
This character is not very strongly marked, and in the 
more highly calcified condition of the cell is often difficult to 
detect. On young zocecia in the marginal region of the 
colony a shallow rounded sinus may be detected, though even 
amongst these cells not unfrequently occur in which the 
margin has all the appearance of being entire. In the case 
of older zocecia, which are overlaid by a thick calcareous crust 
and the orifice is sunk in a comparatively deep shaft, the sinus 
will often be sought in vain. 
It is nght to add that Mr. 8. O. Ridley, who obtained the 
species from Franz-Joseph Land, found the oral sinus ‘ well 
marked in most, even old cells” *. 
Lepralia pertusa, Esper. (PI. VIII. fig. 7.) 
There seems to have been a good deal of uncertainty about 
this species; I have therefore given a figure taken from a fine 
St.-Lawrence specimen in which the characters are well 
displayed. Smitt, in one of his later works +, identifies it 
with his Hscharella porifera (a near ally, if not a mere variety, 
of Smittia Landsborovii), trom which it is separated by 
important differences. Of Busk’s figures one or two are 
referable to another species. Waters, in his ‘ Bryozoa of the 
Bay of Naples,’ has recorded two varieties of Lepralia per- 
tusa, both of which probably are quite distinct from Hsper’s 
species. 
Schizoporella cincta, Wincks, var. (Pl. VIII. fig. 2.) 
Lepralia cincta, ‘ Annals,’ ser. 5, vol. xv. p. 254, pl. viii. fig. 6. 
A variety of this New-Zealand species occurs amongst the 
St.-Lawrence dredgings which is distinguished by a peculiar 
condition of the cell-wall in the immediate neighbourhood of 
the avicularium. In the typical form a prominent umbo rises 
immediately below the orifice, bearing on its summit an elon- 
gate pointed avicularium, placed transversely. In the variety 
the umbo has disappeared or is reduced to a very slight and 
inconspicuous elevation forming part of a distinct area of the 
cell-wall, extending to a greater or less distance below the 
orifice, sometimes almost orbicular, sometimes elongate and 
stretching down about half the length of the cell. This area 
* ¢ Annals’ for June 1881, p. 449. 
+ (Efvers. Kongl. Vet.-Akad. Forhandl. 1878,—No. 7. Bryozoa from 
the Arctic Sea (Peninsula of Kola). 
c.—_—-. 
