ANIMALS. 153 
PECTEN PusILLUus, Schlotheim. Plate XIII, figs. J,1 2, 3. 
(?) New spucius or Pectren, Thomson. Annals of Philosophy, vol. iv, p. 417, 1814. 
Discitges pusttius, Schl. Akad. Miinch., vol. vi, p. 31, pl. vi, fig. 6 a, 5, c, 1816. 
PLEURONECTES PUSILLUS, Schl. Petrefactenkunde, p. 219, 1820. 
<= — » Boué, Edin. Phil. Journ., vol. xu, p. 144, 1825. 
Protgn, (8. N.), J. de C. Sow. Trans. Geol. Soc. Lond., 2d series, vol. iti, p. 120, 1829. 
(?) Prcten priscus, 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. 
— pusiiius, Schl. Miinster., Goldfuss’s Petrefacta, vol. ii, p. 72, pl. xcviii, fig. 8 
a, 6, c, 1835? 
LIMA DISCITES PUSILLA, SchJ. Quenstedt, Wiegmann’s Archiv, vol. 1, p. 81, 1835. 
PECTEN — » Morris, Catalogue, p. 114, 1843. 
— PUSILLUS »  Geinitz, Geea von Sachsen, p. 96, 1843. 
— — », De Verneuil, Bull. Soc. Géol. de France, 2™° serie, vol. i, 
p. 34, 1844. 
Geol. Russ., vol. 1, p. 225, 1845. 
— — » Tennant, Strat. List, p. 88, 1847. 
a — » King, Catalogue, p. 9, 1848. 
— — » Howse, Trans. T. N. F. C., vol. i, p. 250, 1848. 
— — »  Geinitz, Versteinerungen, pp. 10, 11, pl. iv, fig. 22 a, 6, 
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.?) 
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 
Pl. 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.” 
1 This figure represents the shell as too oblique. 
2 «Testa ovato-orbiculari equivalvi subeequilaterali convexa levi, auriculis subrectangulis ineequi- 
lallibus, antica valvze dextree majori subplicata.”’ 
5 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. 
u 
