1864.] • TATE CEETACEOtrS ROCKS OF IRELAND. 43 



Affinities. — Eiheridgia bears some general resemblance to Gamer 

 spongia, D'Orbigny. The general form of the species of that genus 

 is that of two cones opposed by their bases, the inferior one with 

 irregularly disposed oscules, more or less elongated, and attached by 

 the extremity. The upper cone or head, which is very conspicuous 

 and unmistakeable, is smooth, depressed, and truncated. 



I dedicate this genus to my friend Eobert Etheridge, Esq., E.G.S., 

 F.H.S.E., of the Geological Survey, from whom I have received much 

 assistance and encouragement in the prosecution of my geological 

 studies and investigations. 



20. Etheridgia MiRABiLis, spcc. nov. PI. V. figs. 4a, 46. 

 Locality. — Yery common in the Spongarian Zone (Upper Chalk) ; 



Island Magee, Whitehead, and Woodburn especially. 



CcELOscTPHiA, gcn. nov. 

 Polyccdia, E. de From., 1860 (not of King, 1849). 



M. E. de Fromentel, in the ' Memoires de la Societe Linneenne de 

 Kormandie ' (vol. xi. p. 32), describes the characters of a natural 

 section of the genus Scyphia of Goldfuss, under the generic name of 

 Poh/coelia; Dr. A.F.Iioemer,in Bunker's 'Palseontographica' (vol.xiii. 

 p. 30, 1864), adopts De Fromentel's genus. But this term had been 

 ah-eady used by Professor W. King, in 1849, for a new genus of 

 Zoantharia (see also Morris's Cat. p. 62, 1854). Therefore the generic 

 term Polycoelia being thus preoccupied, I propose that of Cosloscyphia 

 for that group of Sponges associated under the generic title Polyccelia 

 by De Fromentel and by Roemer. 



21. CcELoscTPHiA SULCATA, spec. nov. PI. Y. fig. 5. 



Compound, trifid. Spongite cylindrical, short, and proportionately 

 of great diameter, truncated transversely ; opening, with a diameter 

 half that of the spongite, surrounded by a deeply crenulated border. 

 Walls of spongite deeply folded, with from 10-13 rounded ribs. 



Locality. — Rare in the Spongarian Zone (Upper Chalk), Island 

 Magee. 



22. CcELOPTTCHnjM FURCATiTM, spec. uov. PL Y. fig. 6. 

 Expanded circular disk (only part known) ornamented with ten 



rounded elevated ribs, which radiate from a common centre to the 

 circumference of the disk, and which bifurcate near their commence- 

 ment and again at about half the length of the ribs. A few scat- 

 tered oscules appear on the ribs. 



Locality. — In the Spongarian Zone (Upper Chalk), Whitehead. 

 The figured specimen is unique. 



23. CcELOPTTCHiTJM Beleastiense, spec. nov. PI. Y. fig. 7. 



Disk circular, Avith fifteen broad flattened radiating ribs, which 

 bifurcate near their commencement, and increase in breadth as they 

 proceed to the circumference. 



Locality. — The specimen figured was obtained in the White Lime- 

 stone (Upper Chalk), at the Cave Hill, Belfast, by Mr. S. A. Stewart. 



