ANIMALS. 153 



Pecten pusillus, Schlotheim. Plate XIII, figs. 1,^ 2, 3, 



(?) New species of Pecten, Thomson. Annals of Philosophy, vol. iv, p. 417, 1814. 

 DisciTES PUSILLUS, Schl. Akad. Munch., vol. vi, p. 31, pi. vi, fig. 6 a, h, c, 1816. 

 Pletjeonectes PUSILLUS, Schl. Petrefactenkunde, p. 219, 1820. 



— — „ Boue, Edin. Phil. Journ., vol. xii, p. 144, 1825. 



Pecten, (S. N.), J. de C. Sow. Trans. Geol. Soc. Lond., 2d series, vol. iii, p. 120, 1829. 

 (?) Pecten peiscus, Schl. Brongniart, Tab. de Ter., p. 423, 1829. 



Pecten, sp. not determined. De la Beche, Geol. Man., p. 385, 1831 ; Germ. Transl., 



p. 459, 1832; 3d Eng. ed., p. 573, 1833. 



— PUSILLUS, Schl. Miinster., Goldfuss's Petrefacta, vol. ii, p. 72, pi. xcviii, fig. 8 



a, b, c, 1835? 

 Lima discites pusilla, Schl. Quenstedt, Wiegmann's Archiv, vol. ii, p. 81, 1835. 

 Pecten ' — „ Morris, Catalogue, p. 114, 1843. 



— PUSILLUS „ Geinitz, Gsea von Sachsen, p. 96, 1843. 



— — „ De Verneuil, Bull. Soc. Geol. de France, 2™° serie, vol. i, 



p. 34, 1844. 



— — „ Geol. Russ., vol. i, p. 225, 1845. 



— — „ Tennant, Strat. List, p. 88, 1847. 



— — „ King, Catalogue, p. 9, 1848. 



— — „ Howse, Trans. T. N. F. C, vol. i, p. 250, 1848. 



— — „ Geinitz, Versteinerungen, pp. 10, 11, pi. iv, fig. 22 a, b, 



1848. 



Diagnosis. — "Shell ovate orbicular equivalve sub-equilateral, convex, smooth. Ears 

 subrectangular, unequal, the fore part of the right valve in a great degree subplicate." 

 (Goldfuss.2) 



This is a rather tumid, smooth, equivalved, marginally sub-orbicular species, 

 scarcely ever exceeding half an inch in diameter : its byssal notch is rather deep (vide 

 PI. XIII, fig. 2) ; its anterior ear is the longest : the sides of its umbones are nearly 

 perpendicular. 



Pecten pusillus is rather common in the Shell-limestone of Humbleton Hill; but 

 much rarer in the same formation at Tunstall Hill : it is also rare in the inferior beds at 

 Whitley quarry, and in the breccia at Tynemouth Cliff. A specimen was found in 

 the Doggerbank fragment of Magnesian limestone. Dr. Geinitz records its occurrence 

 in the under Zechstein of Corbusen, and in the Zechstein-dolomite of Gliicksbrunn 

 and Liebenstein.^ 



^ This figure represents the shell as too oblique. 



2 " Testa ovato-orbiculari eequivalvi subaequilaterali convexa Isevi, auriculis subrectangulis insequi- 

 lalUbus, antica valvse dextrse majori subplicata." 



^ In the list of Pectens given in Professor Sedgwick's paper in Trans. Geol. Soc. London, 2d series, 

 vol. iii, p. 120, it is stated : "To this list Mr. Phillips has added a circular fluted species, two inches and 

 a quarter in diameter ;" but no fossil has yet occurred to me agreeing with this description. 



