68 THE CRAG POLYZOA. 



of specimens these organs occupy the centre of most of the cells, whilst in other instances, 

 far more rare apparently, they will be found situated on other parts of the cell, as close to 

 the orifice and below it on one or both sides, or on a level with it, that is to say, quite at 

 the summit of the cell on one side, when the avicularium is generally of far larger size, and 

 presents the form of an elongated spoon-shaped process. 

 E. SecffficicMi sometimes occurs in the crustaceous form. 



7. E. MONILIFERA, W. Edwards. PL XI, figs. 1,2, 3. 



Polyzoario pedunculate, palmato, sen multiformi. Cellulis immersis, pyriformibus, 

 elongatis, fronte carinatis, pororura serie longitudinal! unica, duplicive ad latera ornatis ; 

 ostio orbicular!, infra sinuato vel canaliculate, avicularium utrinque ostendente. Ovicellulis 

 nullis. Cellulis fertilibus (?) magnis, immersis, irregulariter inter vulgares sparsis. 



Polyzoarium pedunculate, palmate, or multiform ; cells immersed, pyriform, elongated, 

 carinate in front, with one or two longitudinal rows of punctures on each side ; orifice 

 orbicular, sinuated, or channelled below ; an avicularium on each side of the mouth. No 

 ovicells. Fertile (?) cells large, immersed, dispersed irregularly throughout the polyzoary. 



E. MONILIFERA, M. Edwards, 1. c., p. 7, pi. ix, fig. 1 ; Michelin, 1. c., p. 327, pi. Lxxviii, 

 fig. 10; S. Wood, 1. c., p. 16. 



Habitat. C. Crag, Sudbourn, S. W. ; J. S. B. ; Faluns, Touraiue, 31. E. ; Cleons 

 (Loire-Inferieure)j Sceaux, Thouarce (Maine-et-Loire), Mich. 



This species, which from the great abundance in which it occurs in the Coralline Crag, 

 may be regarded as the characteristic Polyzoon of that formation, has been so well 

 described by M. M. Edwards that it is scarcely necessary to do more than refer to his 

 observations respecting it. The polyzoary exhibits extraordinary diversities of form ; its 

 lobes or divisions varying from slender subcylindrical and ligulate branches, to broad, 

 wavy, foliaceous expansions. All the various forms, however, agree in the circumstance 

 that the growth springs from a contracted, usually hollow, peduncle, slightly expanding at 

 the base, by which it is attached to shells and rocks. The cells in the younger portions 

 are elongated, pyriform and raised in front, especially at the upper part, into a sort of 

 angular ridge or keel, and the surface on each side of the cell is marked with a longi- 

 tudinal row of pores, the rows belonging to two contiguous cells, being separated by a 

 somewhat raised line. The orifice is placed at the summit of the cell, and looks obliquely 

 upwards and forwards ; it is suborbicular, and sinuated in front or below, the sinus being 

 sometimes produced into a channel. And on each side of the lower border of the orifice 

 is a perforated process or tubercle, supposed by M. M. Edwards, as in other species, to 

 represent a gemmiferous capsule. The form of the opening, however, clearly indicates 



