EROM THE INFERIOR OOLITE. 499 



Windsor as well as in the Northampton Sands and Lincolnshire 

 Limestone, has a very wide upward range through the Great Oolite, 

 the Cornbrash, and the Kelloways to the Coral Rag. 



D'Orbigny gives P. vitreus, Rom., as a synonym. This shell is 

 much more circular than the usual figures of P. demissus (vide 

 Phill.), and appears to approach P. disciformis, Schiibl., as figured 

 by Chapuis & Dewalque (pt. 1, t. 31. fig. 2), which, however, seems 

 equal to P. corneus, Sow. The last-named authors, in fact, unite 

 P. corneus and P. demissus of Goldfuss (non Sow. or Phill.), stating 

 that they only differ in " the shape of the wings, which is not a 

 constant character." Waagen, again, seems to consider our shell 

 distinct from P. disciformis, with which Brauns unites it as well as 

 with P. spathidosus, Rom. (a very distinct shell), and doubtfully 

 with P. cingulatus, Goldf., pars, non Phil. 



A variety (v. inutilis, nobis) occurs commonly in the Jurensis- 

 zone of Yeovil Junction, and often shows very beautiful zigzag 

 colour-markings, as in the fragment figured. As it has larger ears, 

 and seems more convex and oblique than the ordinary type, I am 

 uncertain whether it may not prove to be a distinct species. 



Another variety (v. celatus, nobis) is represented by a shell in the 

 British Museum, from Gayton. It is apparently smooth, but, under 

 a lens, it is seen to have several fine, rounded, evanescent radiations 

 in its central region. I have little doubt that if further material 

 were forthcoming, it would be found to be a distinct shell, as I have 

 met with nothing at all resembling its ornamentation. The matrix 

 is dark sandstone, and the shell itself is coloured a bright brownish 

 red, without markings. 



Several instances of the preservation of colouring are found among 

 English Jurassic shells. Pecten valoniensis, Defr., of the Infraliassic 

 beds of Aust, sometimes retains most vividly its brown, blue, and white 

 tints ; and P. similis, Sow. ?, of the Coral Rag, its dull fawn-colour. 

 The brown and white colour-bands of Cyprina picta, Lj^c, of the 

 Murchisoni-zone in the Cotteswolds, are noted in Ann. & Mag. N. H. 

 1850, p. 423 ; and a similar decoration is sometimes seen in Lima 

 strigillata, Laube. " At Minchinhampton both Nerita rugosa and 

 Nerita hemisphcerica are often found retaining dark brown bands, 

 and a figure of Nerita costulata, Sow., v. bicincta, Ph., banded with 

 white and purple, is given by Phillips in his ' Valley of the Thames' ; 

 while Walford describes the tints of Natica cincta, and has in- 

 formed me that he has often noticed remains of colour-bands in 

 a Pecten ef. demissus from his "Transition Bed" of the Middle 

 Lias of Banbury. Traces of delicate purple may be seen in a spe- 

 cimen of Hinnites velatus in the British Museum ; and Rliynchonella 

 radstockiensis may be frequently collected of a very decided dark 

 red hue. 



Pecten ginoensis, Quenst. 



1858. Pecten demissus gingensis, Quenst. Jura, t. 51. fig. 8. 

 1867. P. gingensis, Waagen in Benecke's geogn.-pal. Beitr. vol. i. 

 p. 629. 



