80 MR. A. W. WATERS ON 
scabra; but only in one or two specimens are the lateral avicularia 
found, and then only to some of the zomcia. The suboral 
avicularium is much raised, the rostrum being continued beyond 
the avicularium; there are a row of pores round the border of 
the zocecium, and the ovicell is wide and not punctured. There 
are many points of resemblance to P. concinna, Busk. 
Loc. Gulf of St. Lawrence, Orphan Bay, and off Cape 
Rozier, 38 fath. (H.). If this is Smitt’s species then also Spitz- 
bergen, Novaya Zemlya and Kola; Finland and North Cape 
(Nordgaard). 
Jackson-Harmsworth Exp.: off Cape Mary Harmsworth, 
53-93 fathoms. 
39. Porras SKENEI, Ell. § Sol., var. tRIDENS, Kirchenpauer- 
(Gee ab, amie, 57) 
Cellepora tridens, Kirchenpauer, Untersuchungs-fahrt der Pommerania, 
p. 188, figs. a & 0. 
? Eschara Skenei, var. tridens, Busk, Ann. Mag. Nat. Hist. ser. 2, 
vol. xviii. p. 33, pl. i. fig. 3 (1856). 
Cellepora ramulosa, Manzoni, “ Bry. foss. Ital.” Sitzungsber. K. Akad. 
Wissensch., math.-nat. Cl. vol. lxi. pt. 1, 1870, p. 12, pl. v. fig. 29, pl. vi. 
fig. 30; Waters (part), Ann. Mag. Nat. Hist. ser. 5, vol. iii. p. 196. 
Palmiceliaria Skenet, var. tridens, Hincks, Brit. Mar. Polyzoa, p. 380 ; 
Waters, Zool. Chall. Exp. pt. Ixxix. p. 36 (vol. xxxi.). 
The Porella Skenet group does not furnish sharp lines by 
which the ordinary rather stout P. Skenei, HE. & S8., can be 
readily distinguished from the less stout form with flattened 
branches known as Porella lorea, Alder, which is somewhat 
stouter than the present cylindrical form with oral avicularia, 
usually on well-marked cylindrical processes ; the number of these 
processes in the specimens examined is usually 3, but Kirch- 
enpauer says + are frequent. The Porella elegans, Alder, is 
still more delicate, but so far has only been found where a stouter 
form algo occurs. 
Smitt united Porella lorea (Alder) and Porella elegans (Alder) 
under Discopora Skenei; and it is doubtful whether they will 
permanently be separated, though at present it may be advisable 
to indicate in which form the growth has taken place, and it 
must be remembered that the operculum is much wider and 
shorter in P. lorea, Alder, so that perhaps on this account it 
should be separated. P. bicornis, Busk, of the Crag is also 
closely allied, but it has not been proved to be the same as the 
erect species. 
