4 CRETACEOUS LAMELLIBRANCHIA. 



1SS1. Toldia (Nucula) scapha, K. A. Zittel. Handb. d. Palseont., vol. ii, p. 54. 

 1884. Leda scapha, J. 8. Gardner. Quart. Journ. Geol. Soc, vol. xl, p. 138 



(partim), pi. v, fig. 23 ? (non 21, 22). 

 1884. — spathulata, Gardner. Ibid., p. 139 {partim), pi. v, figs. 31 — 34. 

 ? 1884. — scapha, O. Weerth. Die Fauna des jNTeocom. im Teutoberg. "Walde 



(Palseonfc. Abhandl., vol. ii), p. 46. 

 ? 1898. — — ? A. J. Juices-Browne. Geol. Mag., dec. 4, vol. v, p. 29. 



Non 1S67. — (Nucula) scapha, O. Fraas. Aus dem Orient, pt. i, p. 92. 



Description. — Shell elongate, oval, compressed, a little inequilateral; ventral 

 margin nearly parallel to the dorsal ; rounded anteriorly, tapering slightly and 

 more compressed and pointed posteriorly. Postero-dorsal margin concave ; antero- 

 dorsal straight or slightly convex. Lunule linear. Surface ornamented, except 

 near the anterior and posterior ends, with fine concentric strise. 



Measurements : 



(i) (2) (3) 



Length . . 15 . 13 . . 9 mm. 



Height . . 7"5 . 6*5 . . 5 ,, 



Affinities. — The form of the shell in this species is similar to that of N. lineata 

 (Sowerby), but it is more compressed and generally larger ; the ornamentation 

 also is much finer. 



jV". scapha differs from N. Marise (d'Orbigny) in being relatively longer, less 

 convex, and less pointed posteriorly. It appears to differ from N. scaphoides 

 (Pictet and Campiche) in its greater relative length, in having the postero-dorsal 

 margin less concave, in the finer ornamentation, and its smaller size. 



The form of the shell in N. scapha is suggestive of the genus Toldia, to 

 which it was referred by Stoliczka. 1 I am unable to give a definite opinion on 

 this point, since the specimens which I have examined do not show the interior of 

 the shell. 



Remarks. — Some of the examples considered by Gardner (pi. v, figs. 31 — 34) 

 to be Leda spathulata, Forbes, certainly belong to this species. 



Specimens in th*e British Museum (Gardner Collection, 'No. L 5109), from 

 Atherfield, were referred to N. scapha by Gardner (pi. v, figs. 21, 22, vide supra), 

 but are more convex than that species, and probably belong to N. lineata (Sowerby) 

 (see p. 8). 



Types. — I have not seen the type ; it is not preserved in the d'Orbigny 

 Collection at Paris. Of the specimens figured by Gardner as Leda scapha, the 

 original of his figs. 21 and 22 is preserved in the British Museum; the original of 

 fig. 23 is stated to be in the Woodwardian Museum, but is now missing. Of 

 the examples figured by the same author as Leda spathulata, the original of fig. 32 



1 "Palseont. Iudica," ' Cret. Fauna S. India,' vol. iii (1871), p. 324. 



