AMERICAN JOURNAL 



MATERIALS TOWARD A MONOGRAPH OF THE 

 GADINIIDiB. 



BY W. H. BALL, SMITHSONIAN INSTITUTION. 



The genus Cradinia was instituted by Gray in 1824, for the 

 Patella afra of Gmelin. In 1840 he instituted for it a special 

 family. In his early publications on the subject, he rightly 

 placed it near Siplionaria in his classification. Afterwards, mis- 

 led by the erroneous description of Philippi, he referred it to the 

 Cervicohranchiata, with Tectura and Scurria which have the 

 gills over the neck, and Lepeta which has no gills. Most other 

 authors have followed Gray. 



The Messrs. Adams combine in the sub-order EdriojotJialma 

 the Chitonidce, the Dentaludce, Fissurellidce, Tecturidce, Lepet- 

 idce and G-adiniidce, thus reaching a climax of confusion rarely 

 equalled. Chenu, as usual, follows the Messrs. Adams, but 

 unites a fossil genus (whose affinities are clearly with Eynai'gin- 

 tda, etc.) with Gadinia in the Gadiniidce. 



Keferstein, with a singular misapprehension of its affinities, 

 places Gadinia in the Acmoeidce and refers it to the Tcenioglossa. 



A more thorough examination of the soft parts than that 

 afforded by the single specimen of Dr. Philippi, shows that the 

 first conclusion of Dr. Gray was much nearer the truth than any 

 subsequent references. 



It is a true pulmonate, breathing air by means of a lung and 

 unprovided with gills of any kind. The anatomy shows affinities 

 with the Auriculidce, and the dentition has relations with that 

 family, but more strongly with that of the Siphonariidoe. 



Order PULMONATA. 



Sub-order BASSOMATOPHORA. 



Family GADINIID^, Gray. 



Genus GADINIA. 



Syn. Gadinia, Gray, Tilloch's (London) Philos. Mag. Ixiii, 1824, 

 pp. 214—271. Isis, von Oken, Heft v, col. 460, 1834. 

 Mouretia] Sby. (nee Gray), Proc. Zool. Soc. 1835, p. 6. 



