556 Scientific Proceedings, Royal Dublin Society. 



Zaphrentin ef. enniskilleni, Edw. & H. 

 Several forms are included in this term. Two distinct forms are figured. 



1. Kate Rocks. (PI. XXXVI, fig. 9.) 

 The young stage agrees very well with that of Z. oystermouthensis. 

 A transverse section of the adult stage has the foUowiug characters : — 

 Diam. 9| mm. Wall thick ("8 mm.). Septa slender, twenty-four in number. 

 Cardinal fossula reaching beyond the middle of the section ; inner half 

 parallel-sided, outer half expanding to the wall, bounded by single septum 

 on each side. Cardinal septum short. Alar fossulse well marked, very 

 oblique to plane of symmetry. Septa convex to cardinal fossula. 

 A similar form occurs at K 11 g in the Rush Conglomerate. 



2. EusH Conglomerate, Ell a. (PI. XXXVI, fig. 14.) 



A transverse section of the adult stage has the following characters : — 

 Diam. 9 mm. Septa twenty-three in number. Septal plan as in Z. enniskilleui. 

 Fossula wedge-shaped, tapering towards the centre, bounded by two septa 

 only. Cardinal septum tliiu, and reaching the centre. Septa in cardinal 

 quadrants strongly thickened, especially at their inner ends. Antifossular 

 group rather short and less strongly thickened, their ends meeting. Counter 

 septum shortened. 



Densiphyllum nodosum, sp. nov. (Pi. XXXVl, fig. 13.) 



Tiie specimen described is from the Rush Conglomerate (E lid), but 

 the species was also found in the Kate liocKS, and in the lowest exposed 

 beds of the Rush Slates. 



Transverse section (diam. 8 mm.) : — There are twenty-two major septa, 

 curved throughout concave to the cardinal fossula, and very evenly spaced. 

 Each major septum is strongly thickened, the stereoplasm being thickest a 

 short distance from the wall of the coral, and from that point thinning 

 gradually towards tlie centre and rapidly towards the wall. Thus each 

 septum bears a node-like swelling. Minor septa are present as short blunt 

 teeth. The interseptal spaces have the form of a Y with a long shank and 

 sliort prongs. The cardinal septum is straight and somewhat thinner than 

 its neighbours. Otherwise no septal break is observable. 



At a diameter of 65 mm. the transverse section closely resembles the 

 mature Zaphrentis deiisa. Oar., except that some of the septa exliibit 

 beginnings of nodal thickening. A very young stage (diam. 3 mm.) is the 

 same as tlie young Z. 



