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TERTIARY FAUNA OF FLORIDA 



GIossus cor Oken, Lehrb. der Naturg.. iii.. Zoologie, pt. i, pp. viii., 235, 1815; Gray, Brit. 



An., vii., p. 95, 1851 ; Stoliczka, Cret. Pel. of India, p. 188, 1871. 

 Bucardia communis Schumacher, Essai, p. 146, 1817. 

 Cardita humana Morch, Yoldi Cat., ii., p. 38, 1853 (not Isocardia Morch, loc. cit., ^Meio- 



cardia H. and A. Adams, 1857). 

 Bucardia cor H. and A. Adams, Gen. Rec. Moll., ii., p. 461, 1857. 

 Tychocardia cor Roemer, Conchyl. Cab., Neue Ausg., x., pt. 3, p. 5, 1869. 



To make clearer the history of this genus I have prefixed the synonymy 

 of its type species so far as it bears on the subject. The " heartshells" of 

 the older conchologists included most of the species with conspicuously cordi- 

 form profiles, compressed or cyclodont teeth, or involute umbones. Bucardia 

 of the pre-Linnean writers comprised such forms as Cypricardia, Hippopus, 

 Cardium, Cardita, etc., and in the Isocardia of Klein we find such an assembly. 



In early attempts to segregate the members of this heterogeneous group it 

 was inevitable that the first subdivisions, according to modern ideas, should 

 still be composed of more than one generic group. 



Linne placed the type of this genus first in Cardium and subsequently in 

 Chama, and gave it three specific names before suiting himself. The oldest 

 of these, according to the rules of nomenclature, must take the place of the 

 latest, which is in almost universal use. 



Poll seems to have been the first to separate the group from the Chamas, 

 but his quadrinomial nomenclature forbids us to utilize his names. 



Bruguiere separated under the name of Cardita a group which included 

 the type of Isocardia, as well as a large number of Carditas in the modern 

 sense. 



Humphrey under the name of Trapesimii separated Cypricardia -\- Iso- 

 cardia of Lamarck, and the former having been selected by Megerle to carry 

 the generic name, the name applied by Lamarck to the latter can be retained. 

 The plural name Hippopodes proposed by Meuschen for Isocardia and Hip- 

 popus is not in accordance with the Linnean nomenclature and must be re- 

 jected, though it might fairly be claimed that it was embodied in Lamarck's 

 Hippopus to an extent which left Isocardia free. Isocardium and Bucardium 

 are variants of philologic trifling. Why the name Tychocardia of Roemer 

 should have been proposed, as observed by Stoliczka, is incomprehensible. 



So far as the Tertiary and recent fauna of North America and the 

 x^ntilles are concerned the genus is divided into two groups, Isocardia proper, 

 typified by /. humana L., and the subgenus Meiocardia H. and A. Adams, 

 typified by /. Moltkeana Chemnitz. These groups are feebly separated in the 



