TRANSACTIONS OF WAGNER 

 824 



TERTIARY FAUNA OF FLORIDA 



Shell regular, equivalve, inequilateral, ovoid, widely gaping, with the 

 umboncs anterior; sculpture concentric, feeble, forming flask-shaped exca- 

 vations (chiefly in shells and corals) which arc lined with calcareous matter, 

 or when not protected by the burrow, forming a partial or complete shelly 

 tube to which extraneous matter is attached. Type of the restricted group 

 G. dubia Don. (-f- G. niodiolina Lam.). 



Subgenus SPENGLERIA Tryon, 1862. 



Valves truncated behind, the beaks not so near the anterior end, with an 

 elevated area triangular and transversely lamcllo.se, radiating from the beak 

 to the truncation on each valve. 



Type G. rostrata Spengler (-(- mytiloidcs Lam.). 



Under the impression that the adventitious tube was a constant character 

 Gould separated G. lagcnula (= G. cyinbia Spengler) as a genus under the 

 name of Cncitrbitida (Proc. Boston Soc. N. Hist., viii., p. 22, 1861), but later 

 writers regard the formation of this sort of tube as accidental and possible 

 with any of the species. 



Chama Rctzius is a complete synonvmc of Gastroch&na Spengler. Cuvicr 

 was the first to restrict the genus and to discriminate between Gastrochana 

 proper and Sptngieria. Rocellaria Fleuriau was founded on the type of 

 Cuvier, ten years later, anil Rupettana Fleuriau was confused by Tryon with 

 Rocellaria, probably by heterophemy. 



This genus extends well into the Mcsoxoic, and in the basal Eocene is 

 represented by G. gaincscnsis Harris (Bull. Pal., iv., p. 70, pi. 6, figs. 12, \2a, 

 1896), from the Midway horizon of Georgia, G. Dalli Harris (as Martesia, op. 

 cit,, p. 71, pi. 6, fig. 15), and G. (Spciiglcria /) cimitariopsis Harris (pp. fit., p. 

 70, pi. 6, fig. 13), from the same horizon. From the Claibornian come G. 

 larva Conrad (Am. Journ. Sci., 2d Ser., i., p. 212, pi. 2, fig. 5, 1846; Aldr., 

 Bull. Pal., ii., p. 71, pi. 5, fig. 12, 1895) and G. subbi partita O. Meyer, which 

 has neither been described nor figured (cf. Bcr. Scnck. Ges., 1887, p. 12). 

 Burrows are not uncommon, and have been described by Meyer from Clai- 

 bornc and by Clark from the Eocene of Maryland and Virginia. 



G-astrochsena ovata Sowcrby. 

 (.iiis/n't'/iit'iin in'ii/a Sowcrby, I". /.. S., 1834, p. 21 ; Hanlcy, Dcscr. Cat. Rec. Sli., p. 10, 



pi. ix., fig. 42, 1842; Cpr. Mazatlan Shells, ]i. 15, 1857. 

 Koccllariii I'i'iita Tryon, Moil. 1'holad, p. 49, 1862. 



