16 THE BRITTSH CONULARLE. 



Conularia homfrayi, Salter. 



1866. Conularia homfrayi, J. W. Salter, in Ramsay's Geol. N Wales. Mem. Geol. Suit., vol. iii, ed. 1, 

 p. 354, pi. x, figs. 11—13 (also ed. 2, 1881, p. 562). 



Diagnosis. — Shell large, thin, tapering uniformly; cross-section unknown. 

 Paces flat, apical angle 7° — 10 ° (?). Marginal grooves well marked, edges 

 prominent. Central facial grooves strong, with prominent edges, and flanked by 

 faint secondary grooves. Aperture imperfectly preserved, lobes apparently blunt 

 and not inflected ; apex sharply pointed ; septa unknown. Ornamentation absent. 



Dimensions. — Length 110 mm. Width of face 25 mm. 



Description. — This species is represented by fairly numerous examples, but 

 most are fragmentary and imperfectly preserved. The rocks in which they occur 

 have usually undergone cleavage, and the fossils are sometimes broadened and 

 sometimes greatly drawn out, so that the apical angle of the face cannot be relied 

 on as representing the true angle. The facial ridges and grooves are also difficult 

 to make out for the same reason. The central groove is quite definite, and there 

 appears to be a faint groove close to it on each side. 



Affinities. — This, the earliest of British Oonularias, is most nearly allied to 

 G. corium, which, is found at a slightly higher horizon. It is distinguished from 

 the latter by its smaller size, more rapid tapering, and by the raised edges of the 

 marginal and central grooves. 



Horizon and Localities. — Upper Tremadoc : Garth Hill; Tu-hwnt-yr-bwlch ; etc. 



Type. — Sedgwick Museum, Cambridge (reg. no. 7). 



Conularia linnarssoni, Holm. Plate I, figs. 1 — 4. 



1843. Conularia quadrisvlcata, var. Silurian, J. Portloek, Rept. Geol. Londonderry, p. 393, pi. xxixA, 



fig. 3. 

 1893. Conularia linnarssoni, G. Holm, Hyolithidse och Conulariidse, p. 130, pi. iv, figs. 38 — 40. 



Diagnosis. — Shell small, tapering uniformly ; cross section -square. Faces 

 equal, flat, apical angle 10° — 20°. Marginal grooves well marked, base rounded, 

 edges smooth and prominent. Facial grooves strong, central ; edges sometimes 

 prominent. Aperture unknown; apex sharply pointed; apical septa unknown. 

 Ornamentation absent. Growth-lines strongly marked, regular, horizontal, ending 

 abruptly on either side of the marginal groove, leaving a smooth edge; at the 

 central grooves replaced by fine stria?, bent down towards the apex, and meeting 

 at an angle at base of the groove. Occasionally the growth-lines are hardly 

 visible, and the shell is then quite smooth. 



Dimensions. — Length, 50 — 00 mm. Width of face, 15 mm. 



