PECTEN. 159 
Measurements : 
(1) (2) (3) (4) 
Leneth f 36 : 25 : 22 : 15 mm. 
Height ——. a) 27 : 26 ie 
(1) B. lateralis zone, Speeton. 
(2,3) B. jaculum zone, Speeton. 
(4) Claxby Ironstone, Benniworth Haven. 
‘These measurements are approximate only, on account of the imperfection of the specimens. 
Considerably larger examples than (4) occur in the Claxby Tronstone. 
Affinities —I have seen only a few specimens of this species, and most of them 
are very imperfect, consequently [ am unable to make a detailed comparison with 
allied forms. The species which appears to approach most nearly P. striato- 
punctatus is P. Morini, de Loriol;! it is found in the Portlandian of Swindon, 
Hartwell, etc., and seems to differ from I. striato-punctatus in being less equilateral, 
owing to the greater proportionate leneth and inward curvature of the antero- 
dorsal margin; the ribs are also, on the average, more numerous and closer 
together, but vary somewhat in this respect. 
P. virgatus, Nilsson, and P. curvatus, Geinitz (see below), are also related to I. 
striato-punctatus. 
Remarks.—Romer figured no examples of this species, but erroneously referred 
to Goldfuss’ figure of a Jurassic form (P. lens). A small form found rarely in the 
Gault of Folkestone is perhaps referable to P. striato-punctatus. 
T'ypes.—From the Hils-conglomerate and Hils-clay of Schandelah, Schoppen- 
stedt, and Elhigser Brink. D’Orbigny’s specimens were obtained from the Aptian 
of St. Dizier (Haute Marne). 
Distribution.—Speeton Clay (zones of DB. lateralis, D1, and of B. jaculwm, C 11) 
of Speeton. Claxby Ironstone (zone of Pel. lateralis) of Benniworth Haven. 
? Upper Gault (zone viii) of Folkestone. 
Recorded by Topley (1875) from the Atherfield Beds of Peasmarsh and East 
Shalford, and from the Folkestone Beds of Folkestone. Recorded by Morris from 
the Lower Greensand of Folkestone. 
Prcren (Campronectes) curvatus, Geinitz, 1843. Plate XXIX, figs. 7a, b; Plate 
XXXVII, fig. 16. 
1833. Prcren arcuatus, A. Goldfuss. Petref. Germ., vol. ii, p. 50, pl. xci, fig. 6 
(non Nilsson). 
? 1841. — — F. A. Rimer. Die Verstein. d. nord-deutsch, Kreidegeb., 
p. 51. 
1 De Loriol and Pellat, “ Portlandien de Boulogne-sur-Mer’”’ (‘ Mém. Soe. Phys. et d’Hist. nat. 
Geneve,’ vol. xix, 1866), p. 107, pl. x, fig. 6. 
