CONULARIA SUBTILIS. 33 



The specimen seen in PI. IV, fig. 4 a shows a curious smooth portion of shell 

 just below the fracture. On each side it appears to be quite continuous with the 

 inner less-decorated layer of the shell. In this character, and in its texture, it is 

 quite similar to the apical septa found in so many species. On each side the 

 transverse ridges appear undisturbed, but above their course is very irregular for 

 over 20 mm. The probable explanation of this is, that the shell was injured during 

 the life of the animal, and the injury was repaired by the growth of the inner layer. 



Affinities. — This species is readily distinguished from other British forms by 

 the very coarse ornamentation and the wide, shallow, marginal grooves. In general 

 characters it resembles 0. oelandica, Holm, but the ornamentation is much coarser, 

 the angle of the face larger, and that of the ridges smaller than in the Swedish 

 species. 



Horizon and Locality. — Wenlock Limestone : Dudley. 



Type— British Museum (Nat. Hist.) (reg. no. G. G271). 



Conularia sp. 



Description. — Several fragmentary specimens occur in the Llandeilo rocks of 

 Balcletchie and Dowhill, which should probably be placed in a distinct species, 

 but as there is no example which is at all complete I merely note the characteristic 

 features : Marginal grooves well marked with rounded base, and prominent 

 rounded edges; facial grooves absent. Faces equal, flat; apical angle 10° — 11°. 

 Apex sharply pointed. Ornamentation fairly coarse; ridges (10 — 12 in 5 mm.), 

 forming a sharp curve (= angle of 135°) across the face, bending up again and 

 ceasing abruptly at the prominent edges of the marginal grooves ; smooth near the 

 apex, but finely tuberculated higher up. Furrows slightly striated. 



Dimensions. — Length, 30 mm. Greatest width, 7 mm. 



All specimens are in Mrs. Gray's Collection. 



Conularia subtilis, Salter. Plate IV, figs. 7 — 11. 



1821. Conularia quadrisulcata, Sowerby, Min. Conch., vol. iii, pi. 260, fig. 3. 



1855. Conularia subtilis, J. W. Salter, Appendix A to Sedgwick's Synops. Brit. Palaeoz. Bocks, p. vi. 



1855. Conularia subtilis, F. M'Coy, in Sedgwick's op. cit., p. 288, pi. i, l, fig. 24. 



Diagnosis. — Shell of medium size, tapering slightly more rapidly at the apex. 

 Cross-section rhombic ; diagonals often nearly equal. Faces equal, slightly convex 

 apically and concave aperturally ; average apical angle 13°. Marginal grooves 

 narrow, inconspicuous ; facial groove fine ; central or slightly nearer the " central " 



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