TRANSACTIONS OF WAGNER 

 844 



TERTIARY FAUNA OF FLORIDA 



Corbula (Aloidis) fossata AUlrich. 



Corbula Murchisoni Lea var. fossata Aldr., Journ. Cin. Soc. Nat. Hist., ix., p. 45, pi. 2, 

 fig. 22, 1886. 



Eocene of Newton and Walitnbbee, Mississippi, and of Mt. Lebanon, 

 Bienville Parish, Louisiana (Vaughan). 



This form is very abundant in the Wahtubbee Hills and very constant in 

 its characters. It differs from oniscus in having a furrow before the rostral 

 carinn, behind which the concentric ribs are doubled in number and halved in 

 size, while the carina is more prominent than in oniscus, though the general 

 form is the same. 



Corbula (fossata var. ?) extenuata Dall. 



PLATE 36, FIGURE 6. 



Eocene of the Orangeburg District, South Carolina; Burns. 

 This differs from fossata by being less high and more elongated, with 

 two very strong keels on the rostrum, the end of which is emarginate between 

 them ; the anterior keel projects below the ventral margin of the rest of the 

 valve, with an emargination in front of it ; the rostrum is produced, recurved, 

 and sculptured as in fossata ; the beaks are small, pointed, and incurved; the 

 left valve is smooth and very turgid. Lon 8, alt. 6, diam of right valve 3.3 mm. 



Corbula (Aloidis) perdubia de Gregorio. 

 Lesueur, Walnut Hills Fossils, pi. v., fig. 16, 1829. 



Corbula (Neeerd) perdubia Greg., Mon. Claib., p. 233, pi. 36, figs. 31, 32, 1890. 

 Corbula laqucata Conr., Am. Journ. Conch., I, p. 3, 1865 ; Checkl. For. Fos. N. Am., 



p. 28, 1866. (Name only.) 

 Corbula fifasa Conrad, Am. Joufn. Conch., I, p. 145, 1865 ; not page 137, plate 10, tig. 7. 



Jacksonian Eocene at Jackson, Red Bluff, and near Enterprise, Missis- 

 sippi ; Natchitoches, Louisiana, and Rust County, Texas ; in the Vicksburgian 

 at Vicksburg, Mississippi. 



This species has had some vicissitudes. Conrad named it in manuscript 

 laqueata and included the name in his check-lists, but when he wrote a de- 

 scription he headed it " filosa" a name he had used for another species only 

 a few pages earlier in the Journal. Moreover, in the reference to the figure 

 of the original filosa on page 212 he refers not to the original description, but 

 to the second one. 



The species is notable for the absence of rostral keels, and is usually 

 small, but some of the specimens attain nearly the full size of C. oniscus, I 



