REPORT ON THE POLYZOA. 
61 
(5) Diachoris hirtissima, Heller 
Diachoris hirtissima, Heller, Adriafc., p. 94, pi. i. figs. 6, 7. 
Chaunosia hirtissima, Bk., Quart. Journ. Micr. Sci., vol. vii. pi. xxxvi. figs. 12-16. 
Character . — Zooecia elongated oval ; suberect, very convex behind. Orifice semi- 
circular, with a thin prominent peristome above. The entire surface and borders in front 
and behind beset with longer or shorter pointed spines. Avicularia 0. 
Habitat . — Station 352a, off St. Vincent, Cape Verde Islands, 10 fathoms. 
[Adriatic, Heller.] 
Family X. Membraniporid^e. 
Celleporidae (pars), Jolinst. 
MembraniporidcB (pars), Brit. Mus. Cat., Smitt, Hincks, &c. 
Fliistrellidce, Flustrinidce, Flectrinidce, Escharidce, &c. (pars), d’Orb. 
Biflustridce (sp.), Bk., Smitt. 
Flustradoe (pars), Gray. 
Flustra (pars), Linn. 
Microporidce (sp.), Smitt, Hincks. 
Character . — Zoarium membranous, membranaceo-calcareous or calcareous, encrusting 
and adnate, or erect and free, foliaceous or lobed then bilaminar or polygono-cylindrical. 
Zooecia depressed in front with a raised border, the area filled in by a ehitinous membrane, 
beneath which may be an entire or partial, calcified lamina. 
The numerous and heterogeneous forms which might be arranged more or less artificially 
under the above definition may be conveniently, and to some extent perhaps naturally, 
subdivided into five principal types, which may be regarded, at any rate provisionally, as 
generic, four of which only, however, are represented in the Challenger collection. The 
fifth, for which I should propose to adopt M. d’Orbigny’s 1 appellation Pyripora, would 
include the forms represented by Hippotlioa [Membranipora) ccitenularia of authors. 
The following genera are contained in the Challenger collection : — 
1. Membranipora, Blainville. 
§ a. simplices (no marginal spines). 
(1) Membranipora albicla, Hincks (PI. XV. fig. 4). 
(2) Membranipora crcissimarginata (Hincks). 
Var. a. erecta (PI. XIV. fig. 3). 
Var. b. incrustcms (PI. XV. fig. 5). 
1 Palaeont. Fraruj., p. 538. 
