TRANSACTIONS OF WAGNER 

 7QO 



TERTIARY FAUNA OF FLORIDA 



Mytilus inairvus Conrad, Proc. Acad. Nat. Sci. Phila., vii., p. 29, 1854. 

 Mytilus (Myoconc/ia) incurvus Conrad, Medial Tert., p. 88, 1861. 

 Mytiloconcha incuriia Conrad, Proc. Acad. Nat. Sci. Phila. for 1862, p. 291, 1862. 

 MytilicoHcha incurva Conrad, Proc. Acad. Nat. Sci. Phila. for 1862, p. 579, 1863. 

 Mytiloconcha incrassata Whitfield, Mio. Moll. N. J., p. 38, pi. 5, figs. 10, n, 1894; not 

 of Conrad. 



Oligocene of Sopchoppy Creek, Wakulla County, Florida, Hodge ; Lower 

 Miocene of Cumberland County, New Jersey, at Shiloh and Jericho; of Mary- 

 land, near Skipton, on the Choptank, near Easton, Talbot County, and in Cal- 

 vert County, Harris and Burns ; Miocene of South Carolina, Whitfield. 



The specimens found in New Jersey are very badly worn and young, 

 hence Professor Whitfield's identification of them, which I believe erroneous. 

 I have never seen a perfect specimen of this singular shell, but the external 

 casts from the Upper Oligocene of Florida show its characters admirably. 

 The M. incrassata Conrad is only a rather heavy Alytiliis. The hinge of the 

 present species has two strong teeth in the left and one in the right valve, 

 which are obsolete in senile specimens. These teeth are produced over the 

 cardinal area as ridges, extending to the apex of the valve, with a furrow on 

 each side of each ridge, a single furrow between the two ridges of the left 

 valve. Apart from the furrows and ridges the area is flattened. Close to 

 the posterior margin the groove of the ligament is continued along the edge 

 of the area to the apex. In a specimen one hundred and twenty millimetres 

 long the area is twenty millimetres long and about the same in greatest width. 

 The characters are those of ordinary Mytilus, but curidusly exaggerated. 

 Mytilus hesperiamts Lam., of the Red Crag of Britain, would seem to belong 

 in this group. 



Genus MODIOLITS Lamarck. 

 Modiolus Lam., Prodr. Nouv. Clas. Coq., p. 87, 1799. Type Mytilus inodiolns L. ; Hose, 



Hist. Coq., iii., p. 158, 1802; Link, Beschr. Rostock Samml., Hi., p. 146, 1807; 



Cuvier, Regne Anim., ii., p. 471, 1817 ; Goldfuss, Zool., p. 611, 1820; Risso, Hist., 



iv., p. 323, 1826; Fleming, Hist. Brit. An., p. 408, 1828; Forbes, Malac. Monensis, 



p. 43, 1838 ; Herrmannsen, Ind. Gen. Mai. Suppl., p. 84, 1852. 

 Modiola Lam., Syst. des An. s. Vert., p. 113, 1801. Type M. papuana Lam. (Encyc. 



Moth., pi. 219, fig. i) ; Roissy, Moll., vi., p. 273, 1805 ; Lam., An. s. Vert., vi., p. 



119, 1819; Fischer, Man. de Conch., p. 968, 1886; Dall, Bull. U. S. Nat. Mus., No. 



37, p. 38, 1889. 

 Amygdalum Megerle, Mag. Ges. Naturf. Fr., v., p. 69, 1811. Type A. dcndriticitm Meg. 



(Chemn., xi., p. 198, fig. 2016-7). 



