570 REPORT— -1885. 
2. Chorizopora hyalina. 
Var. Bougainvillei, Busk 
= Escharina Bougainville, D’Orb. 
= Lepralia hyalina, var. Bougainvilla, Busk, ‘Chal. 
Rep.’ pl. xxii. fig. 4; ‘ Kerguelen Polyzoa,’ Busk. 
3. 3 Honolulensis, Busk, ‘Chal. Rep.’ pl. xxii. fig. 12. 
Only one species (No. 1, the type of the genus) is given by Mr. 
Hincks in his ‘ Brit. Mar. Polyzoa.’ 
Genus 67. Porella, Gray 
= Porella, Hincks, Smitt (pars), Gray, ‘ Brit. Mus. Radiata,’ 
= Hschara (pars), Sars., Busk, Alder, Smitt 
= Hemischara and Lepralia, Norman & Busk. 
‘Zoarium erect, ramose, cylindrical, or sub-compressed, or crustaceous. 
and adnate. A median oral avicularium within the primary mouth, with 
a semi-orbicular or sub-triangular mandible.’—Chal. Rep. p. 149. 
1. Porella levis, Fleming (Hincks, ‘ Brit. Mar. Polyzoa,’ p. 334). 
Var. subcompressa, Hincks, ‘Chal. Rep.’ pl. xx. fig. 3. 
The only form described by Mr. Busk, who says ‘that the difference 
between this and the usual cylindrical form of the northern Porella levis 
is sufficient to mark it as a distinct variety.’ Loc.: Cape de Verde. 
Several British species of Porella are described by Mr. Hincks, and 
the list is added to in his descriptions of foreign Cheilostomata. ‘Through- 
out this very natural group,’ says Mr. Hincks (‘ Brit. Mar. Polyzoa,’ p. 321), 
‘there is a striking uniformity, not only in the characters of the adult 
cell, but also in the course of its development; and the study of it has 
done more than most things to convince me that in this section of the 
Polyzoa we cannot safely regard the mere erect and branching habit as 
a generic criterion.’ In further remarks Mr. Hincks points out many 
peculiarities of structure in the several species to which he directs atten- 
tion, 
a. Zoarium incrusting. 
2. Porella concinna, Busk, ‘Brit. Mar. Polyzoa,’ p. 323, pl. xlvi. 
Var. a, Belli, Dawson (id., pl. xlvi. fig. 6). 
» 1, gracilis, Hincks (id., fig. 9). 
Loc.: var. a, Shetland and Gulf of St. Lawrence. 
on aes minuta, Norman, op. cit. p. 326, pl. xxix. figs. 1, 2; pl. 
xxxvl. figs. 6, 8 
= (?) Lepralia chilopora, Manzoni. 
B. Zoarium incrusting, or erect and unilamellate. 
4. Porella strama, Norman, op. cit. p. 329, pl. xxxix. figs. 3, 5 
= Hemeschara id., Norman. 
Loc.: Shetland (rare) ; Bergen. 
y. Zoarium erect ; branches compressed. 
5. Porella compressa, Sowerby, op. cit. p. 330, pl. xlv. figs. 4, 7, and 
woodcut, p. 322. 
