34 SUPPLEMENT TO GREAT OOLITE MOLLUSCA. 
Pecren Micunuensis, Buvignier. Tab. XXXIII, fig. 3. 
PECTEN CANCELLATUS, Bean, on Cornbrash Fossils, Mag. Nat. Hist., 1839 (no figure 
or description). 
— Micae.ensts, Buvignier. Paléont. de la Meuse, Atlas, p. 24, pl. 32, fig. 7. 
Testa orbiculari, depressa maxima, concentrice rugosa et obsolete lineis subpunctatis 
trregulariter radiata, ad umbones costulis converts, distantibus, regularibus radiantibus et 
concentricis decussata; umbonibus acutis; auriculis inequalibus, transverse costellatis. 
(Buvignier. ) 
Shell orbicular, depressed, large, rugose in the adult state, with slightly defined, irregular, 
radiating lines and large, irregular, concentric lamelle ; the umbones are acute, the auricles 
are unequal, the posterior auricle with large, rugose, transverse striations ; the surface near 
to the umbo has regular, radiating coste, slightly knotted where they are decussated by the 
concentric costa, which are nearly regular, and somewhat less closely arranged than those 
which radiate. 
The foregoing description applies to the right valve; the change which the surface 
undergoes in acquiring its adult condition is very striking, and is slightly indicated by the 
few last lamelle upon the specimen figured; a very fine example in the Scarborough 
Museum, from the Coralline Oolite of Malton, shows that it ultimately acquired the aspect 
of Hinnites, thus losing all regularity in its ornamentation, and having very large, irregular, 
squamose lamellz ; the left valve has not been obtained. 
Pecten retiferus («Gr. Ool. Monogr. Biv.,’ p. 9, tab. i, fig. 15) approaches to it in the 
kind of ornamentation, but has the radiating coste larger and more distant, as are also the 
concentric lamelle ; the umbones are less acute, and the auricles, which have a different 
figure, are more nearly equal. Under the name of Pecten cancellatus, it was inserted by 
Mr. Bean in his list of Cornbrash fossils, but without either figure or description. The 
splendid work of M. Buvignier on the ‘ Palzontology of the Meuse’ exemplifies an aged 
specimen, together with the progressive changes which the ornamentation of the surface 
underwent. 
Geological Positions and Localities. The specimen figured is from the Cornbrash of 
Scarborough ; it occurs also in the Coralline Oolite of Malton ; M. Buvignier has recorded 
it in the same formation at St. Mihiel and at Donaument. 
Prcren antsopLeurus, Buv. Tab. XXXIII, figs. 5, 5a. 
PECTEN ANISOPLEURUS, Buvignier. Paléont. de la Meuse, Atlas, p. 23, pl. 19, figs. 
31—35. E 
Testa subrotunda, depressa, inequivalvi ; valva sinistra subplana, quinquecostata, lamellis 
concentricis, fibrosis, interdum tnterruptis, subtextis, ornata; costis distantibus, convexis, 
