CUSPIDARIA. 261 



Affinities. — When describing- tlie Mollusca of the Chalk Rock in 1897 only an 

 imperfect specimen of G. pidciiva was available for study, and 1 identified it with 

 G. camiata (Nilsson). Two better specimens from Norwich have now been seen, 

 and anew figure of Nilsson's type has been published I)y Hennig.' The English 

 form^figured by Sowerby as I^i'da pulrJira — differs from the type of ('. cnndnta in the 

 relatively greater height of the anterior ])ar( of the shell, the more nearly posterior 

 position of the umbones, and in the posterior rostrum proceeding from the \o\d\ 

 of the hinge-line instead of below it. < '. piilrlim approaches closely the specimen 

 figured by Goldfuss" as G. caiuhitu, and it was chiefly on account of this resem- 

 blance that I identified the English form with Nilsson's species. Stoliczka^ and 

 Hennig, however, consider that Goklfuss' specimen is nut an example of ('. cauddta. 

 If all the specimens figured by foreign writers as G. (-midala really belong to that 

 species then it is obviously extremely variable and might well include G. jndchra. 

 Without an oppoi'tunity of studying a series of foreign specimens and a larger 

 number of English examples it seems, at present, preferable to regard G. puirJira 

 as distinct from G. candata. None of the English specimens shows e^'idence of the 

 existence of such a long posterior beak as is present in the type of G. Cdudafa. 



A specimen of Gii.^^iidaria from the Upper Greensand of Uevizes (Plate XLIV, 

 fig. 7) resembles some specimens of G. judrlini and may be provisionally referred 

 to that species. 



Ti/2>e. — The type, from the '• Chalk of Kent," cannot noAV be found. 



Dint ribul ion. — Chalk Rock of Cuckhamsley, Berkshire, and Henley Park. 

 Up|)er Chalk (zone of L'dcniiiilclla niucru)iafa) of St. Giles' Gate and Horstead, 

 near Norwich. 



1 'Kevis. Lamellibr. i Nilssou's Petrific. Suecana Format. Cret.' (1807), p. 62. pi. iii, fig. 28; 

 EavE. ' Molliisk. i Daumarks Kridtafi. I. Lamellil.r.' (1902), p. (35 [133], pi. iv, fi-. 2t. 



- ' Petref. Germ.,' vol, ii (1840), p. 251, pi. cli, fij,'. 17. Compare also WoUymauu, • Seuoiis v. 

 Bieweude' ('Jalirb. d. k, preuss. geol. Landesaust.,' fiir 1900), p. 23, fig. 5 ; Miiller, ' Mollusk. d. 

 Uutersen. v. Braunscliweig u. lUcdc ' (1898), p. 77, pi. x, lii,'s. 10, 11 ; Wolleiiumii. • Fauna dvr Liiue- 

 Imrg. Kreide' (1902). p. 80. 



^ ' Palaiout. Iiidica, Cret. Fauna S. India," vol. iii (1870), p. 41. 



35 



