498 REV. 0. E. WHIDBOKNE ON SOME FOSSILS 



ornamentation in the more distinct portions, and become radial at 

 the margins. 



There are specimens in the Bristol Museum from the HumpJiriesi- 

 anus-zone of Dundry, in the Jermyn-Street Museum, from near 

 Grantham, and in the British Museum from Northamptonshire 

 and the Lower Trigonia-Grit of Leckhampton. 



The species was originally described from the Sowerbyi-zoiie of 

 Gingen. 



It seems to be a very variable shell both in shape and markings. 

 The left valve is sometimes marked similarly to the right, and some- 

 times the radiations almost entirely disappear. 



A fossil in the Sowerby Collection seems to belong to this species. 



Pecten corntttus, Quenst. PL XVI. figs. 1, 2, 2 a. 



1852. Pecten cingulatus, Quenst. Handb. t. 40. fig. 41. 

 1858. P. cornutus, Quenst. Jura, t. 74. fig. 10. 



Each valve smooth, nearly flat, rather longer than wide, orna- 

 mented interiorly by nine or ten rounded radiations, which termi- 

 nate abruptly before reaching the margin. Bight valve with 

 anterior ear moderately notched, posterior ear rather larger. Left 

 valve with ears equal, produced triangularly beyond the umbo, 

 and covered beneath with fine longitudinal striae. 



This shell was at first described by Quenstedt as the P. cingulatus 

 of Phillips, Geol. of Yorkshire, tab. 5. fig. 11, quoted and figured 

 by Goldfuss on his plate 99. fig. 3 (though the English author him- 

 self gives no name in his edition of 1829). In his "Jura," 

 however, he correctly distinguished it, and called it P. cornutus, on 

 account of the horn-like wings. Its internal rays at once separate 

 it from P. demissus, Phill. 



In the Jermyn-Street Museum there are fine specimens of both 

 valves from Bridport, only differing from Quenstedt's figure by 

 being slightly wider, and having, perhaps, less elongated horns. 

 Another from Leckhampton, probably belonging to the same species, 

 has much longer horns, marked at the base by two sharp transverse 

 ridges. As its surface shows some slight signs of tesselation, some 

 of the small specimens common at Dundry and the Cotteswolds, and 

 usually classed as P. personatus, Goldf., may, from their likeness to it, 

 eventually prove to be the young of this form. 



Pecten demissus, Phill. PI. XV. fig. 15. 



1829. Pecten demissus, Phillips, Geol. Yorksh. vol. i. t. 6. fig. 5. 



1835. P. demissus, Goldfuss, Petr. Germ. t. 99. fig. 2. 



1836. ?P. vitreus, Bom. Verst. ool. Geb. t. 13. fig. ?. 

 1849. P. demissus, D'Orb. Prodr. sect. 12, no. 214. 



1853. P. demissus, Lye. & Morr. Gt. Ool. Moll. pt. 2, t. 14. fig. 7. 

 1858. P. demissus, Quenst. Jura, t. 44. fig. 14. 



1864. P. demissus, Seeb. Hann. Jur. p. 101. 

 1869. P. demissus, Brauns, Mittl. Jur. p. 270. 

 This species, which is common and often very large at Dundry, 

 and occurs in the PirTcinsoni-zone of the Cotteswolds and at Broad- 



