138 CARBONIFEROUS CEPHALOPODA OF IRELAND. 



area (especially on the left-hand side of the figure), none of which would have 

 come into view but for the distortion (of. fig. 2 h) . On comparing fig. 3 a with 

 M'Coy's figure ('Synopsis,' pi. iv, fig. L3) it will be seen that the latter is pressed 

 into an elliptical form, the crushing in this case having been exerted in a direction 

 vertical to the plane of the umbilicus and sides of the shell, instead of, as in my 

 shell, oblique to that plane. Thei'e is a specimen in Mr. Wright's collection exactly 

 similar to the one represented in M'Coy's figure, both in its size and in the manner 

 of its distortion. 



Localities. — Cork, IMidleton, Blackrock, in the county of Cork; Glenbane, 

 county of Limerick ; Clane, county of Kildare. 



Perictclus Doohylensls, a. H. Foord and G. G. Grid: Plate XXXVII, figs. 



8 a~c. 



1897. PERicTCLrs Doohylensis, A. H. Foord and G. C. Grid: Cat. Foss. Ceph. 



British Museum, pt. 3, p. 151, 

 fig. 72. 



Description. — The following is the diagnosis of this species given in the 

 ' Catalogue of Fossil Cephalopoda in the British Museum,' from which it vriW be 

 seen that two forms of the species, one being more compressed than the other, 

 were recognised. No new material has been since acquired. 



Shell discoidal, somewhat inflated, umbilicated; greatest thickness near the um- 

 l)ilical margin, from about five-eighths (in the inflated form) to about five-ninths (in 

 the compressed form) of the diameter of the shell ; height of outer whorl from about 

 two-fifths (in the inflated form) to about four-ninths (in the compressed form) of 

 the diameter of the shell. Whorls few, but exact number unknown ; inclusion 

 about three-fourths ; umbilicus deep, exposing the edges of the inner whorls, 

 about one-fourth of the diameter of the shell in width, "\\niorl semilunate (in the 

 inflated form) or semi-elliptical (in the compressed form) in section, wider than 

 high, indented to about one-quarter of its height by the preceding whorl ; 

 periphery broadly convex, sides convex, a little more flattened in the compressed 

 than in the inflated form ; inner margin well defined, convex, nearly- at right 

 angles to the plane of symmetry. 



Body-chamber occupying the Avhole of the last whorl ; aperture with a broad 

 and very shallow peripheral sinus. Suture-line as in PI. XXXVII, fig. 8 c. Test 

 ornamented with numerous very fine, rounded, transverse ribs, separated by rather 

 wider interspaces ; the ribs are nearly direct on the lateral area, and form on the 

 periphery a broad, very shallow, forwardly concave sinus ; they bifurcate near the 

 umbilical mar"-in at rare intervals. The outer wliorl with about four constrictions. 



