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1 IO7 



TERTIARY FAUNA OF FLORIDA 



fig. 9, 1780 (in text wrongly as fig. 8), after Knorr, Vergn., vi., pi. 7, fig. 6; ?not C. 

 latnin " Borne" Reeve, Conch. Icon., fig. 21. 

 Cardium hiulcum Reeve, Conch. Icon., Cardium, pi. xxi., fig. 123, 1845 (fide E. A. Smith). 



> Cardium asfersum Sowerby, P. Z. S., 1833; p. 85; Conchological 111., fig. 15, 1841. 



> Cardium aspcrum Roemer, Conch. Cab., Neue Ausg., Cardium, pp. 76, 122, 1869. 

 Pafyridea soleniformc Swainson, Malac., p. 374, 1840. 



This species has a confused synonymy, owing to the fact that the earlier 

 writers confused several distinct shells under one name, and applied a Linnean 

 name (Solen bullatus) based on a figure, supposed to represent an Area, in" 

 Rumphius's work on Amboyna shells to the present species. I have not access 

 to Gronovius's work, and his species by many authors is cited as identical with 

 C. apertum L., while other authorities refer it to the shell now under considera- 

 tion. The name C. latitm was given by Born to a shell figured by him which 

 closely resembles worn specimens of C. latuin Reeve in the Conchologia 

 Iconica, figure 41. The description, however, as pointed out by Smith (Chal- 

 lenger bivalves, p. 158) might serve very well for the present species, and if 

 identical the name would be prior. I hesitate to accept it, however, on account 

 of the uncertainty referred to and the fact that authors most nearly contem- 

 poraneous and their successors for more than a century have identified the name 

 with the Chinese shell. The earliest unquestionable name is C. spinosum 

 Meuschen, based on a figure of Lister representing a Jamaican specimen of the 

 present species. Meuschen, by the way, also cites Knorr (to which I have 

 not access) for an illustration of his shell, which reference is also given by 

 Born under C. la tit in. 



A careful study of a large number of specimens shows that there are several 

 nearly related forms of this shell, which are possibly specific, but which in the 

 absence of a fuller series from the far East I prefer to rank as varieties. 



Cardium (Papyridea) spinosum var. spinosum s. s. 

 Cardium soleniformc Bruguiere, ex forte. 



Pleistocene of Florida and the Antilles ; recent in the West Indies and from 

 Cape Hatteras, North Carolina, south to Santa Marta, Brazil. 



Shell with about forty-six ribs separated by narrower interspaces, in each 

 of which runs a little, elevated narrow thread; the anterior ribs ( 16) show 

 low arched imbrications, especially towards the margin; the central ribs 

 ( 18) are low and rounded, becoming flatter and wider posteriorly, and are 

 more or less sprinkled with very dehiscent microscopic granulations usually 

 worn off even in living specimens, and more abundant behind the middle part 



