62 THE CRAG POLYZOA. 



Habitat. — Cor. Crag, on Turritella planisphera ; Red Crag, on Nassa, S. W. ; 

 Touraine, on Goryonia and univalve shells, Michelin. 



The habit of this species, which is obviously quite distinct from C. edax and C. pumicosa, 

 is well expressed in M. Michelin's words -. " incrustans, involvens." 



9. C. DENTATA {n. sp.) PL IX, fig. 12. 



Polyzoario adnato, repente ; lepraliseformi. Cellulis subglobosis in crusta calcarea 

 denso ad dimidium immersis ; rostro brevi, forti, conico avicularium gerente munitis. Ostio 

 infundibuliformi, suborbiculari, antice dente lato interno armato. 



Polyzoariuni adnate, spreading ; cells subglobose, half immersed in a dense calcareous 

 layer ; orifice infundibuliform, suborbicular, with a broad denticle within the anterior 

 margin ; a short, stout, conical rostrum supporting an avicularium in front of the orifice. 



Habitat. — Cor. Crag, on shell, S. W. 



A form intermediate between Cellepora and Lepralia. Agreeing with the former in 

 the erect position of the cells and the ascending rostriform avicularium in front of the 

 orifice, and with the latter in the nearly regular disposition of the cells in a single layer, 

 except at the middle of the crust, when they become more irregularly heaped. 



Fam. VI. ESCHABIDj^, Busk. 



Polyzoarium erectum, rigidum, compressum, foliaceum, ramosum, lobatum sen reticu- 

 latum ; e cellulis decumbentibus ad unam vel utramque faciem spectantibus compositum. 



Polyzoarium erect, rigid, compressed, foliaceous, ramose, lobate, or reticulate. Cells 

 disposed in the same plane, on one or both sides of the polyzoarium. 



EscHAUiDiE, Busk, B. M. C, p. 88 ; (pars) Johnston ; D'Orbigny, Auct. 

 Lepraliana and Reteporana, Gray. 



SYNOPSIS OF GENERA. 



1. Two layers of cells. 



a. Layers of cells inseparably united by a distinct calcareous septum. 



1. Eschara. 



2. Melicerita. 



