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TERTIARY FAUNA OF FLORIDA 



Lintcllaria Bucquoy, Dollfus and Dautzenberg, Moll. Roussillon, ii., p. 635, 1898 (err. typ. 



for Lentillaria Schum.). 

 Codakia Dall, Synopsis Lucinacea, p. 797, 1901. 



This is a well-marked group which may be divided into two subdivisions 

 with the following characters : 



Codakia s. s. Shells large, heavy, with more or less distinctly reticulate 

 sculpture ; relatively compressed, with small beaks and lunule ; the ligament 

 and resilium large, deeply inset, the former with a calcareous external coating ; 

 margins entire ; foot moderately elongated. Type Chama codok Adanson. 

 Dental formula L- ioI-ioiq.iqi ^ taken from C. orbicularis L. 



R.olo.oioi.olo 



The posterior lateral teeth are obscured by the growth of the ligament in 

 the adult, but traces of them can almost always be noted. The cardinals are 

 not bifid and the right anterior cardinal is often obscured by the excavation of 

 the lunule in front of it. 



Jagonia Recluz. Shells small, light, frequently tumid, and very inequi- 

 lateral ; beaks more prominent and lunule relatively often larger ; ligament and 

 resilium external, on a narrow nymph, not coated with shelly matter ; posterior 

 laterals distinct ; margins usually crenulate ; foot dififering little from the ordi- 

 nary Pelecypod type. Type Le jagon Adanson, := Venus orbicnlata Montagu 

 + Lucina pecten Lam. In these forms the radial part of the sculpture is 

 usually more pronounced than in Codakia. 



The species of this genus from their general similarity were more or less 

 confounded together by authors until recently. Linne in his original refer- 

 ences in the tenth edition of the " Systema Naturas" correctly differentiated 

 three of the principal forms, two of which he afterwards confounded together. 

 For this reason the specific names have been very generally erroneously applied, 

 notwithstanding these facts were pointed out by Hanley half a century ago. 

 To sum up briefly, the Indo-Pacific region, the West Indian region, and the 

 Panamic province have distinct species of large Codakia, of which the East 

 Indian form is the typical C. tigerina, the West Indian the C. orbicularis, both 

 of Linne, while the C. distinguenda Tryon, from the Gulf fauna, has been 

 confounded with the former and with the very distinct, strictly Indo-Pacific 

 C. punctata of Linne. These blunders appear to have been aggravated by 

 careless collectors, who labelled specimens of unknown provenance with locality 

 marks belonging to the supposed name and not to the specimen. To this day 

 it is uncertain whether the type of the genus described from Senegal by Adan- 

 son is identical with the East Indian form (found at the Cape of Good Hope) 

 or the West Indian shell, though the probabilities are in favor of the latter. 



