104 Mv. R. Etheridge ow Carboniferous Lamellibranchmta. 



laro-e tumid, and prominent beaks of that species ; the con- 

 cen'tric wrinkles or plaits are numerous, and not merely re- 

 duced to three in number as in Prof. M'Coy s species. 



Loc and Horizon. Cockburnspath, near bt. Abbs Ueaa, 

 Berwickshire, in a fine brown sandstone of the Lower Car- 

 boniferous or Calciferous Sandstone series. Collected by and 

 in the cabinet of Dr. Traquair. Mr. Salter obtained a 3%- 

 alina, " species obscure," in the bottom beds of the Cock- 

 burnspath section, and an Avicula or GerviUia m thm sandy 

 layers, with Cyclopteris, of the Cockburnspath coal-beds . 



Genus Nucula, Lamarck. 

 Nucula Youngi, sp. nov. PI. IV. figs. 11-13. 

 Sp char. Transversely elongated, insequilateral, and com- 

 pressed ; anterior side short, much smaller than the posterior, 

 bluntly attenuated ; posterior side elongated, inclined to become 

 square, but with the margin uniformly rounded; umbones an- 

 terior, approximate, compressed ; dorsal margin erect no hinge- 

 area- hinge- teeth ? ventral margm rounded, archmg 



rapidly upwards in the antero-ventral portion ; there appears 

 to be a small lunule ; surface regularly and concentrically 

 striated with sharp, prominent striae. 7 i . ,• ' 



Ohs A small and elegant shell, resembling Nucida brevi- 

 rostris, PhiU.t, but having a much straighter dorsal margin 

 anteriorly, and a less constricted anterior end. N. Youngi 

 appears to be intermediate between this species and mccula 

 accipiens, Sow.^ After searching through all the descriptions 

 of Paleozoic Nvmloi at my command, I have failed to find 

 any which would embrace this form. I nanie the species after 

 Mi- J Younff, of the Hunterian Museum, Glasgow. 



Loc. and Horizon. Orchard Quarry, about three miles south 

 of Glasgow, from shale above the Orchard Limestone, Upper 

 Carboniferous Limestone group. Collected by Mr. James 

 Bennie, to whom I am indebted for the specimen. 



I am much indebted to Mr. Walter Keeping for some notes 

 on P ? fimbrmtus, Phill., to Dr. Traquair and Mr. A Patton 

 for the loan of the specimens mentioned as m their collections 

 and to Mr B N. Peach for again undertaking the arawmg ot 



the fossils. 



Mem. Geol. Survey Scotland, No. 33, E. Lothian, pp. 72, 

 Geol. York. 1836,'ii. p. 210, t. 5 f. 11 «. 



t vjreui. xuiiv. j.--'^^', "■ [■■ 7 - 



X Trans. Geol. Sec, 2nd ser. v. t. 39. f. 40. 



