PECTEN. 157 
Left valve moderately convex, with ornamentation similar to that of the right, 
but the concentric grooves are rather more distinct and not so close together; the 
radial striz are more distinct and cover a larger part! of the valve. Anterior ear 
large, triangular, outer angle about 90°, height nearly or quite equal to length, 
with concentric ridges and radial striz. Posterior ear much smaller and lower. 
Measurements : 
(1) (2) (3) (4) (5) (6) 
Leneth , BOD ae AO ae hoe es Di ee Oman 
Height ; 37 « AQ 2. 54 5, 56 5. “60° 8 78ides, 
Oo > 
(1—5) Perna-bed of Atherfield. 
(6) Lower Greensand of Whale Chine. 
Ajjinities—This species is allied to P. cinetus, but differs in being less convex, 
higher than long, distinctly inequilateral, smaller, in having the concentric grooves, 
and usually also the radial striz closer together, the ears more unequal, and the 
byssal sinus deeper. 
Remarks—A few small specimens (10 to 17 mm. long) from the Atherfield 
Beds of Kast Shalford, in the Me¥er Collection, may be young examples of P. 
Cottaldinus, but they also closely resemble P. Greppini, Pictet and Renevier.? 
Types.—D Orbigny’s specimens came from the Neocomian of Auxerre, ete. 
The specimen referred to 2. circularis by Forbes is in the Museum of the Geological 
Society (No. 2030). 
Distribution.—Perna-bed of Atherfield. Lower Greensand (either Scaphites or 
Lower Crioceras Groups of Fitton) of Whale Chine. Recorded by Topley (1875) 
from the Atherfield Beds of Peasmarsh and Shalford. 
Prcoren (CAMPYONECTES) STRIATO-PUNCTATUS, Ldmer, 1839. Plate XXIX, figs. 4a,b, 5, 6. 
1839. Prcren srriaro-puncratus, . A. Rimer. Die Verstein. d. nord-deutsch. 
Oolith.-geb. Nachtrag., p. 27. 
1841. = = — Die Verstein. d. nord-deutsch. 
Kreidegeb., p. 50. 
1847. : = A. d'Orbigny. Pal. Franc. Terr. Crét., vol. iii, 
p. 592, pl. cceexxyii, figs. 4—7_ 
1850. — — — Prodr. de. Pal., vol. ii, pp. 
83, 119. 
1 Perhaps the whole in perfectly preserved specimens. 
2 «Poss. Terr. Aptien de la Perte du Rhone, ete.’ (1858), p. 154, pl. xix, fig. 4. Pictet and Cam- 
piche, ‘ Terr. Crét. de Ste. Croix’ (1870), p. 198. 
