CARBONIFEROUS FOSSILS OF IRELAND. 18T 



young specimens tliree-quarters of an inch long ; tlicy do not expand so rapidly as tlie adult, but are, at that 

 age, more widely different from the T.fungites. 



TURBINOLIA FUNGITES. Flem. 

 Turbinolia fungites. Flem. Brit. Anim Turbiuolia fungites. Phil. Geol. York. 



Sp. Ch. — Obliquely conical, curved; transversely wrinkled, star concave, lamellae about 1 12. 



Tliis species is liable to great variation in its characters, when young and preserved in shale, exposed to 

 the action of the atmosphere, it is impossible to distinguish them from Turbinolopsis, when old, the number 

 of the lamellaj increases, and transverse septa appear; when very old, it becomes cylindrical, and then ap- 

 proaches very closely to Siphonophyllia; the characters of the species are best known when about two inches 

 lonsr, the star is then about one inch in diameter. 



SiPUONOPUYLLiA CYLiNDRicA. Scolder. MSS. (PI. XXVII. fig. 5). 



The beautiful coral to which my friend, Dr. Scouler, has given the above name, resembles, in some, degree 

 a gigantic specimen of the Turbinolia fungites, it is, however cylindrical for the length of ten or eighteen 

 inches ; the middle of the coral exhibits a number of transverse j)lates, about a line or two distant from each 

 other, and bearing crowded, erect laminae. Down the side of each runs a distinct syphon, from which the genus 

 derives its name ; the interval between the plates and the exterior is occupied by a cellular substance similar to 

 that of the Cystiphyllum of Lonsdale. 



ASTR^A. 



Gen. Ch. — Polypidom, composed of parallel, aggregated, polygonal prisms, terminating each in a stel- 

 lular disc. 



AsTR^A ARANEA. M'Coy. (PI. XXVII. fig 6). 



Sp. Ch. — Stars large, polygonal; very irregular in size and the number of angles; slightly convex, with a 

 large, oval, central hollow or cup, having in the middle a flat, elliptical umbo ; interstices very thin, smooth, 

 straight ; lamellEe about fifty, very delicate, equal (or nearly so), all seeming to reach the centre. 



This beautiful species forms large masses in the limestone of certain localities; the stars are much larger, 

 and less regular in shape, than those of the A. crenularis, or A. he.tagnna, most nearly resembling the A. heli- 

 anthoides in those respects; from this latter species it is distinrjuished by the less number of its lamellte, the 

 oval form of its cup, and the large, compressed umbo. 



ASTR.EA CRENULARIS. PMl. SP. 

 Cyathophyllum crenulare. Phil. Geol. York. 



Sp. Ch. — Discoid; stars unequal, polygonal, their margins prominent, sharp, denticulated; central umbo 

 twisted ; conical cup deep ; lamellae about forty-six, alternately longer and shorter. 



ASTR^A IREEGtJLARIS. Portk. 

 Astraea irregularis. Portk. Geol. Eep. 



Sp. Ch Discoid, stars small ; very irregular in size and shape ; chiefly pentagonal, their margins thin, 



prominent, sometimes undulated ; lamellaj about thirty-five, nearly equal in length. 



This species resembles the A. pentagona, but is distinguished by its more numerous lamellae, nearly all 

 of which reach the centre, while they are alternately longer and shorter in that species. 



