PERICYCLUS FOORDI. 141 



Pericyclus Fooedi, G. C. Crick Plate XXXVIII, figs. 3 a, h, 4. 



1899. Perictclits Foordi, G. C. Crick. Ann. Mag. Nat. Hist., ser. 7, vol. iii, 



p. 430, fig. 1. 



Description. — The following is Mr. Crick's description of this species, drawn up 

 from the original specimen : — " Shell discoidal, somewhat compressed, and rather 

 widely umbilicated ; greatest thickness at the margin of the umbilicus, rather more 

 than two-fifths of the diameter of the shell ; height of outer whorl a little more 

 than three-sevenths of the diameter of the shell. Whorls eight or nine ; inclusion 

 fully three-fourths ; umbilicus rather deep, displaying the umbilical margins of all 

 the inner whorls, about three-tenths of the diameter of the shell in width. Whorl 

 semi-elliptical in cross-section, a little higher than wide, indented to about two- 

 fifths of its height by the preceding whorl ; periphery convex, imperfectly defined, 

 sides feebly convex ; umbilical zone well defined, sloping towards the umbilicus, 

 and making an obtuse angle Avith the sides, rather narrow. 



" Body-chamber not fully seen, but occupying at least one-half of the outer 

 whorl; aperture not seen, but the peristome (judging by the ornaments and the 

 lines of growth) probably with a feeble lateral crest at about the middle of the 

 lateral area and a deep and wide hyponomic sinus. Depth of chambers not seen ; 

 suture-line only imperfectly known. 



" Test ornamented with fine, backwardly directed, and somewhat irregularly 

 spaced riblets, which form rather a low crest at about the middle of the lateral 

 area, and a deep and wide hyponomic sinus on the periphery, where some of them 

 are thicker than the rest and somewhat regularly placed. Up to a diameter of 

 about 56 mm. the test is ornamented with rather coarse, regularly placed ribs, 

 which are separated by interspaces a little wider than themselves, and have the 

 same direction as the ornaments of the adult." 



Dimensions. 



Cast of type specimen Specimen from Clogliran, 

 in Museum of Science in British Miiseum 



and Art, Dublin. (No. C. 7972). 



Diameter of shell . . . 106"5 mm. . 122 mm. 



„ umbilicus (edge to edge) . 42 „ . 48 „ 



„ „ (suture to suture) .32 ,, . 40 „ 



Height of outer whorl . . 47 ,, . 53 „ 



Thickness of shell at umbilical margin . 46 „ . 52 „ 



8uppleme7ifnri/ Description. — By the acquisition of more nearly complete 

 specimens I am enabled to amplify Mr. Crick's diagnosis as follows : — (1) The 



