426 
PALEONTOLOGY OF NEW YORK. 
GLYPTOCARDIA, n. g. 
Glyptocardia speciosa. 
PLATE LXX, FIGS. 2-9; AND PLATE LX XX, FIG. 10. 
Avicula speciosa, Hall. Geol. Surv. N. Y., Rep. Fourth Dist., p. 243, t. 10(5, figs. 1, la. 1S43. 
Cardiola spteciosa (Hall), S. A. Millek. Cat. Am. Pal. Foss., p. 186. 1877. 
“ “ “ Pal. N. Y., vol. v, pt. 1. Plates and Explanations : PI. 70, figs. 2-9. 1883. 
Compare Venericardium retrostriatuM, v. Buck. Ueb. Ammon, p. 50. 1832. 
“ Cardiola retrostriata (v. Buoh), Keyserling. Petschora-Land, p. 254, pi. 11, figs. 3-3e. 1S46. 
“ “ “ “ Sandberger. Yerstein. Nassau, p. 270, pi. 28, figs. 8, 9,10. 1850- 
1856. 
“ “ ? “ “ v.ar. Bohemica, Barrande. Syst. Sil. Boheme, pi. 181, fig-. II, 
1-10. 1881. 
“ Cardium retrostriatum, “ Geinitz. Grauwackenform. in Sachsen, 11, s. 47, taf. 12, fig. 7. 
“ “ pahnatum, Goldfuss. Petref. Germ., p. 217, t. 143, fig. 7. 1837. 
“ “ “ “ F. A. Rcemer. In Dunker and Von Meyer, Palaeontographica, 
Bd. Ill, s. 26/, taf. 4, figs. 11, 12. 1850. 
Shell small, broadly elliptical or sub-circular, sometimes broadly obovate; length 
about one-fourth greater than the height; basal margin regularly curving, 
somewhat obliquely truncate from the beak to the posterior extremity. 
Valves 'regularly convex below, becoming gibbous in the middle and 
descending thence to the beaks. 
Beaks anterior to the middle, closely incurved and directed forward. 
Surface marked by from twelve to fifteen plications; those on the body of 
the shell broad, flattened along their upper surface and sculptured by promi¬ 
nent arching lamellose striae, which are sometimes raised into nodes. The 
interspaces are finely, and inconspicuously, transversely striated. 
Numerous specimens measure 7 mm. in length and 5 mm. in height. The 
smallest specimen observed has a length of 3.5 mm. and a height of 2.5 mm. 
The largest individual in the collection has a length of 10 mm. 
The specimens are subject to considerable variation in form, chiefly owing 
to the direction of the pressure from the enclosing matrix. The plications 
also vary in width and prominence, and in the degree of sculpturing. 
This species has a wide range in New York, occurring in the Hamilton 
group, Genesee slate, Portage and Chemung groups. It is probably identical 
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