78 THE CRAG POLYZOA. 



1. H. IMBELLIS (a. sp.) PI. IV, fig. 6, and PI. X, fig. 7. 



Polyzoario convolute ; cellulis ovatis, suburnbonatis ad marginem presertim punctatis ; 

 ostio semicircular!, labio inferior! recto peristomate simplici. 



Polyzoarium convolute ; cells ovate, punctured especially round the border, subum- 

 bonate in front ; orifice semicircular, with a straight lower border and simple peristome. 



ESCHAKA PERTUSA (?), Michelin, 1. c., pi. Ixxix, fig. 2. 



Fragments of this species may be confounded with Escliara cormita, Lep. variolosa, and 

 L. Jiaimeseana, and perhaps of E. pertusa, although little attention will suffice for their dis- 

 tinction. 1. The species is not adnate, although one layer overlies another. 2. From E. 

 cornuta and L. variolosa it is distinguished by the unarmed orifice, whilst the absence of 

 an introral denticle, and the presence of an umbonal projection on the front of the cell, 



distinguish it from L. Haimescana. 



3. LIBERJE. 

 Fam. VII. SELENARIIDJE, Busk, 1853. 



Polyzoarium liberum orbiculare sen irregulare, conicum sive depressum, supra con- 

 vexum, infra plannm vel concavum ; facie convexa tanturn cellulosa. Cellulis duplicis 

 generis seriatim dispositis seu quincuncialibus. 



Polyzoarium free (?), orbicular or irregular, conical or depressed, convex on one side, 

 and plane or concave on the other ; composed of a single layer of cells, usually of two 

 kinds, which open on the convex surface only. 



SELENARIAD^E, Busk, B. M. Cat., pt. ii, p. 97, 1852. 



ESCHARID^: (pars), TfOrligny, Ann. d. S. N., 3d ser., xvii, p. 284, 1852. 



POLYPIERS FORAMINES (pars), Lamarck, An. S. Vert., 2d ed., ii, p. 299. 



CELLARI/EA (pars), Blainville, Man. d'Actin., p. 448. 



MILLEPOREES (pars), Lamoroux, Exp. Meth., p. 44. 



ASTERODISCINA, Lonsclale, Dixon's Geol., Sussex, p. 159. 



Originally included by Lamarck among his " Polypiers foramines," a heterogeneous 

 group, containing also several genera of Foraminifera and true Corals, and by Lamouroux 

 associated also with Foraminifera and some Corallines, in the order " Milleporees," the 

 true systematic position among the Polyzoa, of the Selenariidse or Lunulites, was first 

 indicated by De Blainville (' Man. d'Actinol.,' p. 448, 1834), who placed them at the head 



