554 Scientific Proceedings^ Royal Dublin Society. 



' Linguln ' mijtiloides, Sow. 

 Athyris glabrutria, Phil., incl. niut. Z2. 

 Spiriferina laminosa, M'Coy. 

 Spirifer clathratus, M'Coy. 



,, rd))ieriainis, de Kon. 

 Martinia pinguis, Sow. 

 Reticularia cf. reticulata, M'Coy. 

 Ambocoelia Urii, Flem. ? 

 Schizophoria resupinata, Mart. 

 RhipidonirUa Michelini, L'Ev. 

 Bielnsma aff. Kingi, de Kon. 



,, ef. sacculus, Mart. 

 Pugnax cf. pugnus, Mart. 

 Camarophoria pleurodon, Phil. 



llusH Slates, lower = Z,. 



These beds should be at the top of Z2 if the previous correlatiou.s are correct. 

 The fauna seems to agree with this position. We may note especially 

 Athyris glabridria, inut. Z2, Zaphrentis delanoui, Chonetes cf. lagmssiana, Spirifer 

 clathratus, and Productus burlingtonensis as characteristic Z forms. Spirifer 

 romerianiis is known from Ci. 



NOTES ON SOME OF THE SPECIES. 

 Zaphrentis cf. densa, Car. (PI. XXXVI, fig. 3.) 



HoI.MPAimCK LlMKSTONE. 



Only one specimen obtained. Younger parts missing. A transverse 

 section near the top is almost identical with Z. densa, Car. (type)/ except 

 that the wall is thicker. A section a little above this (where the structure is 

 probably mature) shows the following differences from Z. densa, Oar. 



(1) The wall thicker still (diam. of sect. 8 mm., thickness of wall 1-5 mm.). 



('2) The septa (28 in number) more slender. 



(3) The fossula more U-shaped. 



(4) The cardinal septum extremely shortened. 



1 Geol. Mag., 1908, PL iv, fig. 7. 



