186 CRETACEOUS LAMELLTBRANCHIA. 



since only imperfectly preserved specimens liave been seen. The oliliqne striae, 

 and the scales on the ribs, however, seem to connect it with /'. liohiudldinus, Init it 

 appears to be distinguished by the regular alternation of large and small ribs, and 

 by its greater size. P. Stutchburianus presents some resemblance to one of the 

 specimens from the Tourtia figured by d'Archiac ^ as /'. acuminatus, Geinitz, but 

 differs in the ribs being closer together and alternating in size. 



Bmnarhs. — The examples from Haldon differ from the type in having the scales 

 on the ribs indistinct, but this difference is probably due to imperfect preservation. 



Type. — Blackdown Greensand ; in the Bi-istol Museum. 



Distribution. — Greensand of Haldon and Blackdown. 



Section ^quipecten, P. Fischer,^ 1886. 

 (' Manuel de Couch.,' p. 944.) 



Pecten (tEquipecten) asper, Lamarcl; 1819. Plate XXXV, fig. 12; Plate 



XXXVI, figs. la,h, 2, 3,4. 



1770. M. Lister. Conch., pi. cccclxx, fig. 28. 



1813. OsTREA MUBiCATA, /. Townseiul. The Character of Moses established for 



Veracity as a Historian, vol. i, pi. i, 



fig- 2. 



1819. Pecten asper, Lamarck. Auim. sans Vert., vol. vi, p. 180. 



1820. Pectinites asper, E. T. v. Schlothenn. Die Petrefactenkunde, p. 226. 

 1822. Pecten asper, /. de C. Sowerby. Miu. Conch., vol. iv, p. 95, pi. ccclxx, 



%. 1. 

 — — — A. Bronrjniart. Descr. geol. Envir. de Paris (in Cuvier's 



Oss. Foss., vol. ii), pp. 320, 603, pi. v, 

 fig. 1. 

 182o. — — Defranre. Diet. Sciences nat., vol. x.Kxviii, p. 261. 



1832. — — G. P. Deshayes. Encyc. Moth. Vers, vol. iii, p. 728. 



1833. — ~ A. Gohlfms. Petref. Germ., vol. ii, p. 58, pi. xciv, fig. 1. 



1836. — — G. P. DesJiaycif and H. Milne Edwards. Ed. 2 of Lamarck's 



Auim. sans Vert., vol. vii, p. 157. 



1837. — — F. Dujardin. Mem. Soc. gcol. de France, ser. 2, vol. ii, 



p. 228. 

 ? — — — var. POLONicA, G. G. Pusck. Polens Palaeont., p. 41, jjI. v, 



fig. 7. 

 1839. — — H. B. Geinitz. Char. d. Schicht. u. Petref. des sjichs. 



Kreidegeb., pt. 1, p. 23. 



1 ' Mem. Soc. geol. de France,' ser. 2, vol. ii (1847), pi. xvi, fig. 3 (on the left-hand side, not the 

 other fig. 3). 



^ I follow Dall in regarding JEnuipecfrn as only a section of Chlamys. See ' Trans. Wagner 

 Free Instit. Science of Pliiladcliihia,' vol. iii (1H;»8). p. 695. 



