CARBONIFEROUS FOSSILS OF IRELAND. 41 



This magnificent fossil is rarely of a less size than that figured in the plate, and frequently reaches six 

 inches in diameter; the surface is almost perfectly smooth; the keel, which is very large and square, is much 

 nearer to the base than the centre of each turn ; and the portion of each whorl below the keel is so convex as 

 to give a channeled appearance to the sutures ; the spire consists of six whorls, the keel extending to all of 

 them ; the upper whorls appear rounded, as in the plate, only when the outer shell is absent, as was tlie case 

 with the specimen figured ; umbilicus deep, conical, smooth. Length three inches, width four inches three 

 lines. 



Pleurotomaria Hainesii. M'Coy. (PL IIL tig. 8). 



Sp. Ch. — Conical, depressed; spire small, of three roimded volutions, having the band part above and 

 part below the suture, basal whorl lenticular, depressed above and below, rounded at the circumference, where 

 there is a narrow, prominent, square band ; surface above marked with strong, equal sulci, slightly curved 

 where they set off from the spire, and extending obliquely backwards to meet the band at a very acute ano-le ; 

 sui'face below the band smooth, or faintly striated across. 



This beautiful species is dedicated to Dr. Haines, of Cork, who obligingly lent the specimen fio-ured. 

 Length five lines, width eight lines. 



PlEUROTOMARIA HELICINOIDES. MCoy. (PI. VII. fig. 6). 



Sp. CA.— Obtusely conical, lenticular, smooth; last whorl carinate; whorls convex beneath; concave 

 towards the outer edge, convex towards the suture above ; umbilicus small, rounded. 



This shell closely resembles the Euomphalus Qualteriaiuis, but is known from it by the very small size 

 of the iimbilicus, which, in the latter species, is so large as to expose the whorls. Diameter four lines ; height 

 of spire two lines. 



PlEUROTOMARIA L^VIS. M'Coy. (PI. V. fig. 15). 



Sp. Ch. — Very depressed, discoid; whorls narrow, obtusely rounded at the circumference; spire ob- 

 tuse, of three small whorls ; mesial band narrow, flat, subsutural ; surface smooth ; umbilicus laro-e, rounded. 



This shell has its band concealed on the spiral whorls by the sutures, as in tlie P. abdita, Phil., from 

 which it differs in being umbilicate, and much more depressed. Diameter three lines ; height of spire one line 

 and a half. 



PlEUROTOMARIA multicarinata. M'Coy. (PL V. fig. 16). 



Sp. Ch. — Acutely conical; height and width about equal; body whorl small; spire of five or six rounded 

 or subquadrangular whorls ; each whorl with three or four large prominent keels on the middle, above which 

 are four smaller ones, and beneath which, on the flattened base of the body whorl, are numerous small, spiral 

 keels, or sulci, all crossed by very fine, transverse striae ; umbilicus moderate. 



This species in size and shape exactly resembles the P. conica, Phil., but is easily distinguished by its 

 greater number of keels ; the body whorl is very little larger than that which precedes it ; the mouth is roimd, or 

 slightly angulated, base rather flattened. Diameter one inch three lines ; height one inch four lines. 



PlEUROTOMARIA tornatilis. Phil. Geol. York. 

 A few very imperfect fragments, probably of this species, but unfit for description, have occurred. 



MuRCHisoNiA. D'Archiac and De Verneuil. 



Gen. Ch. — Elongate, turreted; spire very long, of numerous whorls; keeled; generally striated obliquely ; 

 umbilicus verv small, or none; a deep, narrow slit in middle of right lip; mouth nearly round; base short. 



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