CALYMENE PLANIMARGINATA. 137 



pairs of graduated lobes, the basal ones not showing such a great increase in size 

 over the second as in C. senaria, auct. ; by its wide, flattened, slightly upturned 

 frontal border ; and by its short frontal lobe. The posterior lateral furrow 

 bifurcates inwardly, as in G. senaria, auct. The axial furrows are not sigmoidal in 

 their course, but gently arched outwards. 



There are well-marked but poorly preserved specimens from Craighead in 

 Mrs. Gray's collection. The pygidium, of which there are also specimens from 

 Craighead, is more pointed posteriorly, longer, and less transverse than in 

 G. blumenbachi. 



Collections. — Mrs. Gray ; Museum of Practical Geology. 



Horizons and Localities. — Stinchar Limestone Group (Llandeilo) : Craighead. 

 ? Balclatchie Group (Llandeilo) : Ardmillan Brae. 



3. Calymene planimarginata, sp. nov. Plate XVII, fig. 15. 



? 1843. Calymene brevicapitata, Portlock, Greol. Rep. Loudond., pi. iii, fig. 3. 



? 1848. Calymene brevicapitata, Salter, Mem. Greol. Surv., vol. ii, pt. i, p. 341, pi. xi, tigs. 1, 2. 



? 1854. Calymene brevicapitata, M'Coy, Synops. Brit. Pal. Foss. Woodw. Mus., p. 165, pi. i f, fig. 6. 



1854. Calymene baylei, M'Coy, ibid., p. 165, pi. i f, figs. 8, 8 a, 8 b. 



? 1854. Calymene brevicapitata, Morris, Cat. Brit. Foss., 2nd ed., p. 102. 



1865. Calymene senaria, Salter (e. p.), Mon. Brit. Trilob., p. 97, pi. ix, figs. 8, 10, 11 (non figs. 9, 



?6, ?7). 



1877. Calymene senaria. Woodward (e. p.), Cat. Brit. Foss. Crust., p. 29. 



1879. Calymene blumenbachi, Nicholson and Etheridge (e. p.), Mon. Silur. Foss. G-irvan, fasc. ii, 

 p. 140 (non pi. x, figs. 2—6). 



1898. Calymene senaria (Salter, non Conrad), Pompecki, Neues Jahrb. fiir Miner., vol. i, p. 197. 



1899. Calymene blumenbachi (e. p.), Mem. Greol. Surv., Silur. Rocks Brit., vol. i, Scotland, pp. 518, 

 672, 688. 



Specijic Characters. — -This species is easily distinguished from C. blumenbachi, 

 auct., by the shape of the glabella, the small frontal lobe, the flattened, instead of 

 rounded, frontal border and the granulose, instead of tuberculated, surface. It 

 agrees with C. caractaci, Salter, in the shape and nature of the frontal border, but 

 differs in the shape of the glabella and lateral lobes. 



Remarks. — The species called " C. senaria, Conrad," by Salter is a composite 

 one, as Pompecki has pointed out. Of the figures given by Salter (op. cit.) only 

 fig. 9 on pi. ix can be considered as representing the C. senaria, auct., as held by 

 Emmons, Hall, Meek, and White, though Pompecki is in doubt whether it is 

 really the same form as Conrad meant. Salter's fig. 9, pi. ix (op. cit.), was drawn 

 from a Trenton Limestone specimen. The other figures given by Salter of 

 G. senaria (pi. ix, figs. — -8, 10, 11) represent British individuals; of these 

 figs. 6 and 7 are the original figured specimens of G. brevicapitata, Portlock, 



18 



