98 THE CRAG POLYZOA. 



2. H. RETEPORACEA, M. Edwards. PL XIV, fig. 2. 



Polyzoario contorto, cavernoso ; ramis contiguis, subcylindricis. Cellularum orificiis 

 confertis, irregulariter dispositis, prominulis sive superficie sequatis, orbicularibus, 

 expansis. Superficie anteriori porosa; posteriori scrobiculata seu cribriform! (non 

 sulcata). 



Polyzoarimu much contorted, cavernous ; branches close, subcylindrical ; mouths of 

 cells crowded, disposed irregularly, exserted or level, orbicular, expanded ; anterior 

 surface porous; posterior pitted or cribriform (not silicate). 



II. RETEPOKACEA, M. Edwards, 1. c., p. 21, pi. x, fig. 2 ; S. Wood (?) ; J. Morris (?). 



Habitat. C. Crag, M. Edw. ; 8. Wood. 



This is the only species among the Crag Ilornerce in which the dorsal surface is not 

 sulcate or costate, but, on the contrary, uniformly pitted, the pits in many cases becoming 

 deep pores, giving the surface a cribriform aspect. In this character, as well as in the 

 convoluted mode of growth, the present form agrees with //. reteporacea of M. Edwards, 

 who says of it, that the " face dorsale des branches est comrne reticulee," although this 

 appearance is not represented in his figure. 



3. H. CANALICULATA (. Sp.) PI. XIV, fig. 3. 



Polyzoario explauato, flabelliformi (?) ; rarnis crassis, subdistantibus ; feuestris magnis, 

 ellipticis seu ovatis. Cellularum orificiis immersis, sursum spectantibus ; subquincun- 

 cialibus. Superficie anteriori obscure reticulata, rarissime punctata ; supra orificia fossam 

 canaliculatam non raro etiam poruni unicum ostendente ; posteriori subplana, granulosa, 

 longitudinaliter sulcata ; sulcis poris distautibus, elongatis munitis. 



Polyzoarium expanded, flabelliform (?) ; branches thick, rather distant ; feuestrae large, 

 elliptical or oval ; mouths of cells immersed, looking upwards ; with a canalicular depres- 

 sion, and usually a pore above ; irregularly quincuncial ; intermediate surface very rarely 

 perforate, very obscurely reticulate ; dorsal surface flattened, expanded at the border of 

 the fenestree, coarsely granular, deeply and irregularly sulcate ; sulci with elongated, 

 distant pores. 



Habitat. C. Crag, S. Wood; J. S. B. 



