BRYOZOA FROM FRANZ-JOSEF LAND. 85 
mandible also has not the cross thickenings characteristic of 
typical Porella, but has a central lucida. There is, however, a 
small group, left for the present doubtfully under Perella, 
though probabiy a genus will have to be made for it when it is 
fully worked up. In this group the avicularian chamber is very 
broad, and in the species which have been studied contains a pair 
of large avicularian glands. The opercula, instead of the long 
muscular ridges of typical Porella, has muscular dots which may 
be a little elongate. The mandibles have no cross bars, but have 
a central lucida. The group at present consists of P. saccata, 
Busk, P. acutirostris, Sm., P. obesa, sp. uov., P. inflata, sp. nov., 
and probably P. (Lepralia) margaritifera, Quoy & G., and 
P. marsupium, MacG. 
44. EscuarorpeEs Sarsit, Smitt. (Pl. 11. figs. 21-23.) 
Escharovdes Sarsii, Smitt, “ Krit. Fort.” 1867, pp. 24 & 158, pl. xxvi. 
figs. 147-154. 
I do not think that either Eschara grandipora of Blainville or 
E. lobata of Lamarck are synonyms. 
Smitt gives the avicularium as triangular, and on this ground 
it is separated from L. rosacea, Busk ; but in the specimens now 
examined, and also in a specimen from the Gulf of St. Lawrence, 
the mandible is rounded at the distal end, though Hincks speaks 
of the pointed mandible. Looking down on the avicularium, it 
may appear triangular, but none of the mandibles that I have 
been able to examine, either in my own collection or in the 
British Museum, including the one described by Ridley from 
Franz-Josef Land and the ‘ Challenger’ specimens, have I seen 
a triangular mandible or one that could be called “acute.” 
With these very small avicularia a mistake is easily made unless 
the mandible is prepared out. The mandibles are not sym- 
metrical and the amount of irregularity varies, as also the size ; 
but in the Chilostomata the avicularia generally are subject to 
considerable variation in size, whereas as a rule the opercula are 
in a species all of one size, often in a specimen all the opercula 
‘seem to correspond in size most exactly. 
The operculum is thin, transparent, membranous, with a 
thickened bar across. 
The ovicell is but little raised, and sometimes there is an 
elongate area in front. The small avicularium occurs within the 
peristomial aperture. 
Some branching pieces of Z. Sarsii, Sm., and Porella compressa. 
