LONSDALE ON THE CRETACEOUS CORALS OF NEW JERSEY. 75 



intermediate stages were not noticed ; but in specimens believed to 

 be far advanced towards extreme age (e, f) the surface of the cells 

 was convex, instead of being concave ; all traces of lines of separa- 

 tion were obliterated, the mouth was irregularly shaped, sometimes 

 with a tooth -like projection on the proximal lip, and the whole 

 surface of the branch was beset with perforated or abraded ve- 

 sicles.* No instance of a perfect filling up of the mouth, which 

 would characterise perhaps the oldest condition of the coral, was 

 noticed. A due preservation of the specimens, which exhibited 

 these stages, forbade any attempt to trace a connection between the 

 vesicles and the polype cells ; but a transverse section of a mature 

 branch exposed clearly capillary tubes, passing through the sub- 

 stance of the thick external covering of the cell. 



The lateral and terminal foramina in the walls of the cells were 

 well exhibited. The former, two in number (see figure g\ were 

 relatively large, situated near the extremities of the cell, and 

 close to the dorsal wall. In one beautifully exposed specimen, the 

 presumed use of these foramina in the formation of cells was 

 instructively shown. The specimen (figure g) displayed the sec- 

 tions of a series of cells with thickened parietes, and the lateral 

 foramina, also the rounded edge of the branch composed of a 

 regular double row of small cells, divided longitudinally by the usual 

 middle or dorsal layer of separation. The mouths of these cells 

 were small and round, and might be mistaken for lateral foramina ; 

 but the boundaries of the diminutive cells, to which they were the 

 regular openings, were clearly to be traced. The length of these 

 imperfectly developed cells was about half that of the full-grown ; 

 and the mouths accorded in position with the situation of the lateral 

 foramina. It is, therefore, inferred, that each minor cell was pro- 

 duced by means of one lateral foramen, the perfect development 

 not having taken place, owing to the absence, in the same longi- 

 tudinal row, of a full-grown anterior cell. In consequence of the 

 quincuncial arrangement of the perfect cells, each polype had, by 

 means of the lateral and terminal foramina, immediate connection 

 with six other cells. 



Cases of monstrosity or deviation from the normal form occur, 

 as before mentioned, near the edges and at the bifurcation of the 

 branches ; but it is believed that some entire branches were com- 

 posed of irregularly-shaped cells, and might, without care, have 

 been assigned to a distinct species. 



No traces of accessory vesicles were observed, nor any satisfac- 

 tory signs of a gemmuliferous vesicle. In one case the whole sur- 

 face of a cell was deeply depressed (fig. d), and might have formed 

 a receptacle for the development of gemmules. 



Locality. Timber Creek, New Jersey. 



* These vesicles or bladders must not lead to the inference that there is any 

 resemblance between Eschara digilata and the recent coral Cellepora cervicornis. 

 In the former case the bladder .has no regular cellular structures, while in the 

 latter there is always a perfectly developed mouth, with accessory vesicles. 



