* Cells more or less open in front, with raised margins.

(Fig. 14.)

Gen. 1. Membranipora, Johnston. Polyzoary encrusting (or suberect, foliaceous, and contorted), spreading irregularly. Cells more or less irregularly disposed or quincuncial, with raised margins; a greater or less extent of the aperture occupied by a thin membrane Eschara (pars), Pallas.

Flustra (sp.), Linn.; Esper; Berkeley; Lamarck;
Grant; Fleming; Risso; Johnston; Lamouroux.
Membranipora, Johnston; 'Brit. Mus. Cat.,' p. 56;
W. Thompson; Hassall.

Discopora (pars), Lamarck.

Annulipora, Conopeum, Callopora, Amphiblestrum, Micropora, Gray.

Eighteen species.

Family 12. Selenariada, Bask.

Polyzoary more or less regularly orbicular, convex on one side, plane or concave on the other (probably free). Furnished with large and powerful vibracula, with variously formed setæ (probably locomotive).

Selenariada, Busk; Brit. Mus. Cat., p. 97.
Gen. 1. Cupularia, Lamouroux.

(Fig. 18; vide also figs. in CELLARIA.) Each cell throughout the polyzoary with a vibraculum at the summit.

Cupularia, Lamouroux (proposed); Brit. Mus. Ca p. 97.

Lunulites, Lamouroux (pars); Defrance (pars); De longchamps (pars); Goldfuss (pars); De Blainvile (pars); Gray; Cuvier and Brongniart; Lonsdale (pars); Michelin (pars).

Fenestella (pars), Lonsdale.

Five species (recent); numerous fossil.

Gen. 2. Lunulites, Lamouroux.

Cells arranged in series radiating from the centre and bifurcating as they advance; vibracula in linear senes alternate with those of the cells.

As in the preceding species.

Four species (recent); numerous fossil.

17, Eschara foliacea. 18,

ria Lowei. 19, Vincularia ornata.

Gen. 3. Selenaria, Busk.

Only a certain number of cells, dispersed at uniform dis

tances apart, furnished with vibracula. The front of each cell furnished, covered by a cribriform calcareous expansion; the others arched above and contracted below.

Lunulites (pars), Busk, Voyage of Rattlesnake.'
Selenaria, Brit. Mus. Cat.,' p. 101.

Sub-Order II. Cyclostomata.

Family 2. Idmoneada.

Polyzoarium continuous throughout, usually polymorphous.

(Fig. 22.)

Gen. 1. Idmonea, Lamouroux. Openings of cells disposed in transverse or oblique alternate series on each side of the front of the branches of the

Tubuliporina, Milne-Edwards.

Tubuliporida, Johnston.

Auloporina (pars), Ehren berg; Johnston.

A. Erectæ.

Polyzoary erect, free, simple or branched, linear or expanded above; branches articulated or continuous.

Family I. Crisiada, Milne-Edwards.

Polyzoarium divided into distinct internodes, connected by a horny substance.

Gen. 1, Crisidia, Milne-Edwards.

A single cell in each internode.

Sertularia (pars), Linn.; Berkeley (pars); Esper (pars).
Cellularia (pars), Pallas; Hogg.

Cellaria, Ellis and Solander (pars); Lamarck (pars).
Eucratea, Lamouroux (pars); Risso (pars); Fleming
(pars); Templeton.

Unicellaria (pars), Blainville.

Crisidia, Milne-Edwards.

Crisia (pars), Johnston; Hassall (pars), &c.

One or two species.

Gen. 2. Crisia, Lamouroux.

Two or more cells in each internode.

rows of cells.

Retepora (sp.), Lamarck.

Hornera (sp.), Defrance.

Idmonea, Lamouroux; Blainville. Three or four species recent; many fossil.

Gen. 2. Pustulipora, De Blainville. (Fig. 26.) Openings of cells disposed irregularly, on all sides of the cylindrical or compressed branches or lobes of the polyzoary. Ceriopora (pars), Goldfuss.

Idmonea (sp.), De Blainville.

Pustulipora, Blainville; Milne-Edwards; Johnston.
Tubulipora, (sp.), Couch.

Five or six species recent; many fossil.

Gen. 3. Hornera, Lamouroux.

Openings of cells disposed irregularly, or in more or less regular opposite transverse series, on one side only of the branches or lobes of the polyzoary..

Millepora (sp.), Esper.

Retepora (sp.), Lamarck.

Hornera, Lamouroux; De Blainville; Milne-Edwards. Several species recent; many fossil.

B. Adnatæ, s. decumbentes,

Obelia, Quoy and Gaimard,

20, Crisia bicellata; a, ovicell. 21, Alecto granulata. 2, Tdmonea radians; a, natural size. 23, Tubulipora serpens.

Anguinella, Van Beneden.

Family 2. Alcyoniada, Johnston.

Cells fleshy, immersed, angular; mouth terminal, simple, contractile.

Halcyonellea, Johnston.

Polyzoa carnosa, Gray.
Alcyoniada, Johnston.

Alcyonidula, Johnston.

Gen. 1. Alcyonidium, Lamouroux.

Polyzoary variously lobed, massive, fleshy, erect, or adnate. Alcyonium, Ellis; Baxter; Pallas; Linn.; Olivi; Esper; Müller; Lamouroux ; De Blainville; &c. Alcyonidium, Lamouroux; Gray; Hooker; Johnston; W. Thompson; &c.

Halodactylus, Farre; Van Beneden.

Cycloum (sp.), Hassall.

Sarchochitum (?), Hassall.

Three or four species.

Sub-Order IV. P. Pedicellinea, Gervais.

Lophophore produced upwards on the back of the tentacles, uniting them at their base in a sort of muscular calyx.

Family 1. Pedicellinide, Johnston.

Gen. 1. Pedicellina, Sars.

Order II. Polyzoa hippocrepia, Gervais.

Tentacles disposed on a crescentic or horse-shoe shaped lophophore; eversion of endocyst only partial. Polypiaria hippocrepia, Gervais.

Polyzoa hippocrepia, Gray.
Lemniades, Johnston; Allman.