104 Mr. R. Ethcridge r)/i ('arho)i(ferotis LameUihranchiata. 



large, tumid, and prominent beaks of tliat species ; the eon- 

 centric 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 St. Abbs Head, 

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

 boniferous or Calciferous Sandstone series. Collected by and 

 in the cabinet of Dr. Traquair. INIr. Salter obtained a My- 

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

 burnspath section, and an Avicula or GervilUa in thin sandy 

 layers, with Cyclopterls, of the Cockburnspath coal-beds*. 



Genus Nucula, Lamarck. 

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



Sp. char. Transversely elongated, inequilateral, 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 margin rounded, arching 



rapidly upwards in the antero-ventral portion ; there appears 

 to be a small lunule ; surface regularly and concentrically 

 striated with sharp, prominent stride. 



Ohs. A small and elegant shell, resembling Nucula hrevi- 

 rostris, Phill.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 Nucula 

 accipienSj Sow. J After searching through all the descriptions 

 of Palaeozoic Nuculce at my command, I have failed to find 

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

 Mr. J. Young, 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.'i jimhriatus^ Phill., to Dr. Traquair and Mr. A. Patton 

 for the loan of the specimens mentioned as in their collections, 

 and to j\Ir. B. N. Peach for again undertaking the drawing of 

 the fossils. 



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

 t Geol. York. I830,'ii. p. 210, t. 5. f. 11 a. 

 \ Trans. Geol. Soc. 2nd ser. v. t. 39, f. 40. 



