Yol. 65.] CARBONIFEROUS LIMESTONE OF COUNTY CLARE. 573 



Athyris hibernica, nom. nov. (PL XXVI, fig. 5.) 



Athyris phalceiia (M'Coy); Athyris squamigera. de Kon. & Davidson. 



This species, though incorrectly referred to Phillips's Spirifer 

 phalcena, was first described by M'Coy in 1844. 1 In 1857 Davidson 

 figured and described M'Coy's actual specimen 2 under the name 

 of Athyris squamigera, a species first described by L. G. de Koninck 

 in 1851, 3 and stated that he had communicated his specimens 

 to the latter, who with some hesitation referred them to this 

 species. 



The strongly-marked ornamentation shown in de Koninck's 

 figures, together with the shape and relative dimensions of the shell, 

 would appear, however, to distinguish it at once from M'Coy's 

 type, which is transversely elongated and has very feeble concentric 

 ornamentation. 



In 1887 4 L. G. de Koninck again described A. squamigera, and 

 stated that he had grave doubts whether M'Coy's form figured by 

 Davidson belongs to the same species ; and a comparison of the two 

 figures can only lend strong support to this view. M'Coy's type is 

 common in the Syringothyris Zone of Clare, and, as the original 

 name of Athyris phalcena by the law of priority belongs to Phillips's 

 Devonian form, I have substituted the new specific name hibernica, 

 this shell at present being only known from Ireland. 



Description : — 



' Transversely oval, much broader than long ; valves convex, sometimes 

 gibbous; beak in the ventral valve moderately produced, incurved and trun- 

 cated at its extremity by a small circular aperture. In the dorsal valve there 

 exists a prominent broad mesial fold, and in the ventral a corresponding sinus 

 of variable depth, both commencing at a short distance from the extremity of 

 the beaks. Surface with small imbricating strise.' 



The concentric striae are the more strongly marked, and probably 

 indicate the original presence of fringed ornamentation as in 

 Athyris glabristria ; in fact, this shell may ultimately prove to be 

 an extremely transverse variant of that species. 



Athyris lamellosa (L'Eveille). (PI. XXVI, fig. 4.) 



A form similar to that figured by Dr. Sibly 5 occurs commonly at the 

 base of the Zaphrentis Zone in County Clare. The shell-expansions 

 are, however, seldom preserved, although the two series of concentric 

 ridges resulting from their fracture are well shown in the figure of 

 a young specimen. 



1 ' Syn. Oarb. Limest. Fossils of Ireland ' p. 140. 



2 ' Monogr. Brit. Foss. Brach.' (Paheont. Soc.) vol. ii, p. 83 & pi. xviii, fig. 13. 



3 ' Description des Animaux fossiles du Terrain Carbonifere de Belgique ' 

 (Suppl.) p. 667 & pi. lvi, fig. 9. 



4 Ann. Mus. Eoy. Hist. Nat. Belg. vol. xiv, pp. 82-83. 



6 Quart. Journ. Geol. Soc. vol. lxii (1906) pi. xxxii, figs. 1 a & 1 b. 



