IDMONEIDiE. 101 



On the anterior aspect the surface between the scattered openings of the cells is 

 uneven, usually retaining but indistinct traces of its original wavy fibrillation, or obscurely 

 reticulate and punctured. The mouths of the cells are depressed, and either simple and 

 orbicular or surrounded with a distinct annular peristome. 



6. H. PERTUSA {n. sp.) PI. XIV, fig. 7. 



Polyzoario parvo, depresso, elongate ; rarais brevibus, insequalibus. Superficie 

 anteriori porosa ; posteriori irregulariter sulcata, sulcis poros crebros magnos ostenden- 

 tibus ; cellularum orificiis orbicularibus, immersis, in seriebus longitudinalibus irregulariter 

 dispositis. 



Polyzoarium small, depressed, irregularly branched, elongated in one direction. 

 Anterior surface very porous ; mouths of cells orbicular, depressed, disposed irregularly in 

 longitudinal series ; posterior irregularly sulcate, with large frequent pores. 



Habitat. — C Crag, S. Wood. 



Notwithstanding the general character of the growth in this species, in which it 

 appears to approximate to the succeeding, it seems from its more minute characters to 

 demand specific recognition. 



7. H. flippOLYTA (?), Defrance. PL XIV, figs. 8, 9. 



Polyzoario depresso ; ramis cylindricis, divaricatis, gracilibus, inaequalibus. Superficie 

 anteriori punctis perparvis ornata ; posteriori longitudiualiter costulata, sulcis porosis. 

 Cellularum orificiis in seriebus transversis, irregularibus dispositis, prominulis, integris 

 supraque porum rotundum plerumque ostendentibus. 



Polyzoarium ramose, depressed ; branches cylindrical, divaricate, slender, uneven ; 

 mouths of cells usually disposed irregularly in transverse rows ; raised, orbicular, 

 usually with a pore above each ; anterior surface nearly smooth, finely punctured ; 

 posterior finely sulcate ; sulci with rare, minute puncta. 



HoRNERA HiPPOLYTA, M. Edwurds, 1. c, p. 21, pi. X, fig. 2. 



— HIPPOLYTHUS, Defrance, Diet. d. Sc. Nat., xxi, p. 432, p. xlvi, fig. 3; Blainville{^.); 



Michelin. 



— nippOLiTHUS, Reuss. 



Habitat. — C. Crag, S. Wood; Grignon (Seine-et-Oise), Hauteville (Manche), 

 Michelin ; M. Edw. 



