GASTEROPOD FAUNA IN THE MILLSTONE GRIT OF SCOTLAND. 



337 



stone, so there is no doubt the beds from which these fossils were obtained overlie it, 

 though the bed has not been recognised in situ. 



Upper Carboniferous plants were got in this mine at 270 feet above the Castlecary 

 Limestone. The species determined by Mr Kidston are Sigillaria elegans, Sternb. 

 (abundant), Lepidodendron obovatum, Sternb., Lepidodendron aculeatum, Sternb. 



co_ 



Gap.. 

 Fireclay 3". \ 

 Slaty C< >AL 3". 

 Pale grey Clay Shale, with scattered 

 hard nodules weathering yellow, Calc 1 / 

 becoming more abundant at base. f ' 

 Hard Rib, with hard clayey matrix -v / 

 and many hard, yellow, weathering \/ 

 nodules, slightly calcareous. J 



Gap. 



= Blaes. 



■ ~ /Red Slaty Ironstone 



Clay Shale, mottled pale grey and red. 

 Mottled red, white, and yellow Sandstone. 



]\1 assive 

 yellow 

 Sandstone, 

 pebbly 

 in parts. 



Gap. 



Fireclay, rather pale grey. 



/Bastard Ironstone. 

 / Blaes. 



Ironstone Rib with shells. 

 \ Blaes. 



Calcareous Blaes. 



Dark grey slialy LIMESTONE. 



Dark grey Clay Shale. 



v 





Blaes 3". 



Gap. 



Sandstone. 



Sandstone and some Fakes. 



** ' : -T"^ ! l/Ccarss pebbly Rib with Clay galls Pyritss 

 - i .,<• remains 



~ : — [and plant 



j I tULj \ yS c [ castlecary Limestone (top post). 



r Chonetes, sp. 



Derbya, sp. 



IAngula mytiloides 

 (cf. M artinia glabra). 



Orbiculoidea nitida. 



Productus (cf. longispinus). 



Pugnax pugnus. 



1 Seminula ambigua. 



? Spiriferina cristata. 



Aviculopecten obliqnus. 

 ,, regidaris. 



? ,, negtectus. 



Clenodonta Iwvirostris. 



Edmondia senilis. 



? Grammatodon tenuistriata. 



Myalina Venieuillii. 



Nuculana attenuata. 



Pterinnpecten j>apyrace\is. 



Sanguinolites occidentalis. 



Euphemus d'Orbignyi. 



Goniatite (cf. Glyphioceras diadema). 

 ^ Orthoceras, sp. 



Fig. 5. — Vertical Section of Strata in Bilston Burn, near Pol ton, Midlothian. 



PART II. 



Specific Descriptions. 



PalsBolima retifera, Shumard, sp., 1858. (PI. I. fig. 1.) 



Lima retifera, Shumard, 1858, Trans. St Louis Acad. Set., vol. i. p. 214. 



,, Geinitz ? , 1866, Garb, und Dyas in Nebraska, p. 36, pi. ii. figs. 20, 21. 

 ,, „ Meek and Hayden, 1872, Fin. Rep. U.S. Geol. Surv. Nebraska, p. 188, pi. ix. 



fig. 5. 

 Palxolima retifera, Bolton, 1907, Q. J. Geol. Soc, p. 462, pi. xxx. fig. 10. 



Specific Characters. — Shell small, oblique, triangularly ovate, very moderately 

 gibbose. The anterior border only slightly curved, the inferior broadly rounded, the 

 posterior oblique and almost straight. The hinge line is short and straight. The 

 umbones are subcentral and sma]l. The anterior ear is small, compressed, triangular ; 

 the posterior very similar, and almost the same size. The valve is flattened near 

 the anterior border and expands gradually so that the greatest convexity is near the 

 posterior border, where the valve becomes bent on itself so as to form a flattened 

 posterior surface. 



Interior.— The shell is ornamented with many angular radiating ribs, somewhat 



