TRANSACTIONS OF WAGNER 

 1356 



TERTIARY FAUNA OF FLORIDA 



Thiatisa Gray, P. Z. S., 1847, p. 195, No. 682, not 680. 



Lucinidea Barrois, in Zittel, Traite de Pal., ii., p. 95, 1887 (err. typ.?). 



Shell tumid or compressed, suborbicular, with feeble sculpture ; lunule 

 narrow, elongate, an obscure anterior dorsal area indicated, but no posterior 

 area or escutcheon ; ligament almost or wholly internal, obsolete ; the resilium 

 deeply immersed ; hinge with the posterior laterals and right anterior cardinal 

 usually absent ; margins entire, anterior adductor scar long and narrow ; dental 

 formula '^■"°"- . 



R. roioo. 



The type of this genus is the Tellina lactea of Gmelin and Lamarck, but 

 not of Linne, whose shell, represented by his original type, is the Diplodonta 

 globnsa of Forskal (as Venus), It. obs., p. 53, No. 122, 1780 (Chemnitz, 

 Conch. Cab., vii., p. 36, pi. xL, figs. 430-31, 1784). The name of Gmelin, being 

 preoccupied by Linne, should be rejected, and the species denominated Loripes 

 lucinalis (Lamarck, An. s. Vert., v., p. 49, 1818), that being the specific name 

 next in date. Other synonyms are Lucina leucoma Turton, Dithyra Brit., pp. 

 1 12-13, pl- vii., fig. 8, 1822; L. amphidesmoides Deshayes, Enc. Meth., ii., p. 

 375, 1830; Thyatira lactea Gray, Ann. Mag. N. Hist., xxii., p. 272, 1847; Lu- 

 cina lacteoides Deshayes, Expl. Sci. Algerie, pi. Ixxx., figs. 1-4, 7, 8, 1848; and 

 Lucina elata Locard, Coq. Mar. de France, p. 313, 1892. 



The genus Megaximis Brugnone, which has some resemblance to Loripes, 

 has been placed as a synonym under it by several authors. By the examina- 

 tion of specimens kindly lent by the Marquis de Monterosato and received by 

 him from Brugnone I have been able to determine that this shell is Thyasiroid 

 and not Lucinoid. It differs from the typical Thyasira only by the greater 

 development of the ligament and resilium, which are strong and set upon strong 

 nymphs and set deeply in an impressed, narrow escutcheon, somewhat as is 

 the ligament in Codakia. The hinge is edentulous and the other characters 

 recall Thyasira, and I have accordingly referred it to that family as a synonym 

 of Thyasira. It has an anterior angle as in T. bisecta, a rather deep lunule, and 

 only incremental sculpture. The ligament was not covered, as it is in Loripes, 

 and neither ligament nor resilium are truly internal. 



Though there are some American recent species, so far none has been found 

 fossil in our Southern Tertiaries. 



Genus MYRT.S3A Turton. 

 Myrtcsa Turton, Dithyra Brit., p. 133, 1822. Sole ex. Venus spinifera Montagu, Test. 

 Brit., p. 577, pi. xvii., fig. i, 1803 ; Gray, List. Brit. An., p. 98. 1851 ; H. and A. Adams, 

 Gen. Rec. Moll., ii., p. 468, 1857. 



