TRANSACTIONS OF WAGNER 

 798 



TERTIARY FAUNA OF FLORIDA 



This form differs from Lithophaga especially by the presence of a row of 

 small but well-defined scars, extending in a radial manner towards the lower 

 posterior basal angle of the shell, within the pallial line. These almost give 

 the impression, when observed casually, of the presence of a pallial sinus. 

 In the absence of fresh specimens of the animal I am unable to determine 

 the function of these scars. 



There are a few species of Modiohts named in the literature which belong 

 elsewhere. M. spiniger H. C. Lea (Trans. Am. Phil. Soc., ix., p. 244, pi. 35, 

 fig. 30, 1845) is perhaps a Crcuclla ; the spines are probably due to some 

 extraneous organism ; it is from the Miocene of Petersburg, Virginia. M. 

 sitbpontis Harris (Bull. Pal., iv., p. 49, pi. 3, fig. 6 a, 1896), from the Midway 

 Eocene of Georgia, has the aspect of a Modiolaria. M. lumstonia Harris 

 (Proc. Acad. Nat. Sci. Phila. for 1895, p. 46, pi. i, fig. i), from the lower Clai- 

 bornian of Texas, is probably a Lithopliaga, and specimens from the Orange- 

 burg District of South Carolina, referred to his species by Harris, are certainly 

 so. It should be carefully compared with L. subalvcata Conrad, from the 

 Lower Miocene of Cumberland County, New Jersey. M. tennis Meyer (Ber. 

 Senckenb. nat. Ges., 1886, p. 10, pi. ii., fig. 7) is a Crcnclla, and identical with 

 C. latifrons Conrad (1860), from the Claibornian and Jacksonian Kocene of 

 Alabama. 



Genus LITHOPHAG-A Bolten. 

 Lithophaga Bolten, Mus. Bolt., p. 156, 1798; Ed. ii., p. 109, 1819; Miirch, Cut. Yoltli, 



p. 55, 1853. 



Lithophagus Megerle, Entwurf., p. 69, 1811 ; Dall, Bull. 37, p. 58, 1889. 

 Lithodomus Cuvier, Regne An., ii., p. 471, 1871. 

 Lithetcimus Nitsch, Ersch et Grub. Encycl., Sect, i, p. 175, 1825 ; Voigt, Cuv. Thierr., 



iii., p. 616, 1834. 



Lithodoma Verany, Cat. An. Invert., p. 13, 1846. 

 Lithodomus Fischer, Man. Conch., p. 969, 1886. 

 Leiosolcmis Cpr., Mazatlan Cat., p. 130, 1856. 

 Myoforcepifvsf&Ri, Man. Conch., p. 969, 1886. 



The type in each of the first three cases cited is Mytilus lithophagus 

 Linne. This was a compound of two species, the most common and best 

 known of which was the Mediterranean form, which received the specific name 

 of dactylus from Sowerby. 



The genus may be divided into sections as follows : 



Lithophaga Bolten, s. s. Shell subcylindric, with nearly terminal beaks ; sur- 

 face polished, with no calcareous incrustation. Type L. dactylns Sby. 



