MUSEUM OF COMPARATIVE ZOOLOGY. 257 
When I first received these valves I supposed that they would turn out to 
be identical with some one of Conrad’s Tertiary species; but after comparing 
with them all, I found that none of them agreed sufficiently well with the re- 
cent species to render it desirable to refer it to either of them. The nearest 
of the fossil forms to the C. floridana is the C. undulata Conrad (not Sowerby), 
of the variety figured by him on Plate XI. of his Fossils of the Tertiary For- 
mations of the United States, which (though dated 1838 on the title-page), ex- 
cepting the first few pages, was not issued until 1845. From this C. floridana 
differs in being more pointed anteriorly and less so behind; in having flatter 
and less pointed beaks; in having a more pronounced flexure below the ros- 
trum, and the latter proportionately shorter, higher, and more ridged above ; 
the cardinal teeth are more oblique, and the anterior lateral does not run up 
in front of the cardinals, but ceases near their lower extremity. I find these 
differences to hold good through a large series, and consequently conclude that 
the recent species is distinct. It is entirely different from the C. antillarwm, 
until now the only recent species of Crassatella proper known to inhabit the 
Antilles. 
The margins of C. floridana are smooth at all stages, but the outside grooving 
in aged specimens becomes obsolete near the margin. 
Suspcenus ERIPHYLA Gass. 
Eriphyla Gabb, Pal. Cal., I. p. 180, 1864; Stoliczka, Pal. Indica, III. p. 156, 1871 
(but not pp. 181, 182, pl. vi.;—= Dozia Bosquet, 1868). Type E. umbonata 
Gabb. 
Eriphylopsis Meek, Inv. Pal. Upper Missouri, p. 125, 1876. Type E. gregaria Meek 
and Hayden. 
The genus Eriphyla of Gabb was poorly figured, and hastily, or at least 
imperfectly, described by its author, for whom, however, allowance should be 
made on account of his isolated position in California, far from well-equipped 
museums or libraries. Meek, who was one of the most careful and exact 
paleontologists, examined into the subject, and found that there could be little 
doubt that the differences between the type of Eriphyla and the small Crassa- 
telloids formerly included under Gouldia, and best known by that name (and 
for his purposes best typified by C. mactracea Linsley), were essentially these. 
The teeth appeared to be reversed as regards the valves, and there was a little 
furrow behind the beaks which by Gabb and himself was supposed to indicate 
the presence of an external ligament, the internal cartilage when absent, as 
in dead valves or fossils, leaving no evidence of its existence. In 1871 Sto- 
liczka complicated the problem by referring to Dozia lenticularis Goldfuss as 
the type of Hriphyla; and by describing that group from the peculiarities 
of the aforesaid Dozia (which probably belongs near Dosinia). This error 
has been copied from Stoliczka into Tryon’s Structural and Systematic Con- 
VOL. XII. — No. 6. 17 
