200 CARBONIFEROUS CEPHALOPODA OF IRELAND. 



occurrence in the Coal Measures, and present in all the specimens of G. Listeri 

 I have met with from that horizon. 



It is interesting to learn that Mr. James Perrin Smith, who lias already done 

 much good work in the embryology of the ammonoids, has made known the 

 occurrence for the first time in America of Gdstrioceras Lister!, associated with the 

 nearly related species G. carbonarlum and other Gkmiatites (Glyphioceras {-Spheno- 

 ceras] crenistria, G. [$.] striatum, G. [Beyrichoceras] calyx)} 



Locality. — Firoda, a townland and also a hamlet, two and a half miles north- 

 west of Castlecomer, county of Kilkenny. (The specimen probably came from 

 Firoda colliery, in the Kilkenny coal-field, but as the only locality given is "Firoda" 

 it is not possible to allocate the specimen with precision.) 



Gastpjoceeas ctrcumplicatile, sp. nov. Plate XLIX, figs. 12 a, b, 13. 



Description. — Shell small, somewhat inflated, widely umbilicated ; greatest thick- 

 ness at the umbilical margin, about one-half of the diameter of the shell ; height 

 of outer whorl a little less than one-third of the diameter of the shell. The number 

 of whorls probably five or six ; inclusion so nearly complete that only the edges of 

 the inner whorls are exposed. Umbilicus rather less than one-half of the diameter 

 of the shell in width, deep, with subangular margin. Whorl semilunate in section, 

 the height about three-fifths of the breadth ; indented to about one-half of its 

 height by the preceding whorl. Periphery broadly convex, the central part 

 elevated into an obscure ridge ; the narrow lateral area somewhat flattened, merg- 

 ing in the periphery. The ornamentation is very elaborate, and therefore difficult 

 to give an adequate conception of by means of a description. It consists of a series 

 of acute transverse ribs bordering the umbilicus and radiating therefrom, with a 

 decided inclination towards the aperture. These ribs, which only extend to the 

 width of the lateral area, give rise to a series of fine, raised, crenulated lines ; the 

 latter generally bifurcate twice in taking their course from the ribs across the 

 periphery. The space between each set of bifurcating lines is filled up with from 

 three to four simple lines, which do not, like the ribs, spring from the edge of the 

 umbilicus, but from a point nearly on a level with the bifurcating lines just 

 described. Thus there is a space left between the ribs devoid of any transverse 

 lines ; but this space is not quite smooth, for it is occupied by the fine spiral lines, 

 here uracil stronger, that cover the whole test. The direction taken by the trans- 

 verse lines upon the surface of the test is as follows: — Starting from the ribs, they 

 curve first forwards and then more sharply backwards, forming a deep and some- 



1 "The Carboniferous Ammonoids of America," 'U.S. G-eol. Surv.,' Mon. xlii, 1903, pp. 1 — 211, 

 29 plates. (Author's abstract in ' Geologisehes Oentralblatt,' Bd. hi, No. 13, p. 680.) 



