197 
M. Walch describes a similar fossil, Supp. PI. v. c. p. 151, as a very 
rare shell, which was found at Guntershofen, and which, he thinks, 
might be very well placed among the tellenites. A similar fossil had 
been previously found at Neustrelitz, in Mecklenbourg, in a grey 
lime-stone, and described and figured in Magazin de Berlin, t. iv. 
This shell M. Walch describes as having the point of the hinge 
elongated; and striae, or raised, elongated, and rather oblique ribs, 
of which, those which are nearest the hinge unite and form an angle. 
The analogue of this shell, he observes, has not yet been found. M. 
Martini observes, with respect to this shell, that he has never seen 
any recent or fossil shell resembling it, having these converging striae, 
in the form of a bow, with cordiform interstices. 
LETTER XIY. 
PHOLAS. . . . FISTULANA. . . . TEREDO DICERAS ACARDO. . . . 
RADIOLITES. . . CHAMA. . . . SPONDYLUS. . . PLICATULA. . . .GRYPHiEA 
.... OSTREA. 
Lamarck, in his Systeme des yinimauoc sans vertebres, had placed 
Pholas at the end of the equivalved shells, and characterized them 
as having accessory pieces ; and the genera Teredo and Fistulana he 
placed at the head of the inequivalved shells, and distinguished them 
as having the principal valve tubular. 
Since that period, in his Suite des Memoires sur les Fossiles des 
Environs du Paris, under the article Fistulana, he says, that he was 
for a long time perplexed, whilst endeavouring properly to charac- 
terize this singular kind of shell, because he considered, as all other 
naturalists had done, the tubular sheath which enclosed the animal 
