78 MR. A. W. WATERS ON 
from the Mediterranean are closely allied, but the branches of 
P. compressa are much the broader, and in the British specimens 
there are several layers of zocecia in the older parts. In the 
Arctic specimens the branches are compressed, and about 4 mil- 
limetres broad, which is about the same sizeas those of P. saccata 
and Escharoides Sarsit. In P. cervicornis there is a bifid 
denticle on the bar of the avicularium. There are also 
differences between the mandibles of Porella cervicornis, M. Kd., 
and those of P. compressa, which, though not very great, would 
alone indicate the probability of these being two distinct species. 
The Franz-Josef Land specimens have 18 tentacles, and oral 
glands, but no avicularian glands were seen. There are two 
distal, and four lateral rosette-plates. 
Loe. Spitzbergen, Greenland, Jan Mayen (Lorenz), Novaya 
Zemlya, 30-60 fathoms ; Kara Sea (Smitt) ; Finland ; Norway ; 
Bohus Bay ; British seas and north coast of France. 
Jackson-Harmsworth Exp.: off Cape Mary Harmsworth, 53— 
93 fathoms. 
36. PoRELLA GLACIATA, sp. nov. (Figs. 2, 3.) 
? Eschara cervicornis, forma Lepralie, Smitt, “ Krit. Fort.” 1867, 
pp. 23 & 149, pl. xxvi. figs. 136, 137. 
A specimen “off the glacier between Cape Flora and Cape 
Gertrude” is in most respects like P. inflata, sp. nov., but. the 
entirely different operculum and mandible show that they are 
quite distinct (see woodcut, figs. 2 & 3). The operculum is very 
broad, and has a very muscular ridge, and the mandible corre- 
sponds with that of a Porella sent to meas P. propinqua, Sm. 
(Pl. 11. fig. 15). 
Fig. 1. Fig. 2. Fig. 3. : 
monem 
i} ee 
AX!) 
xas x 250 
Fig. 1. Lepralia cruenta. Figs. 2, 3. Porella glaciata. 
There is a row of pores by the border with ridges between the 
pores as in P. acutzrostris, Sm. (Pl. 10. fig. 10). 
The surface of the zoccia and of the globular ovicells is 
granular, the peristome is raised at the side, the avicularian 
chamber is wide and distinct with the mandible within the peri- 
stome, but on the top of a more or less tubular projection. 
