Meyer. ] 1 42 [March 16, 
distinctly anteriorly. They approach in their form Astarte coheni Conr.* 
and Astarte symmetrica Conr.{ and indicate that the species has been 
derived from the usual trigonal form of Astarte. A similar recent shell, 
judging from the figure, seemed to be Astarte quadrans Gould, but a 
comparison of specimens proved that there is no resemblance. 
Leda pygmea ? Muenster. Fig. 7, 7a. 
?*Nucula pygmea Muenster, Goldfuss, Petref. German. Vol. ii, p. 157, 
Pl. 126; fig. 17. 
Small ; triangularly ovate ; subequilateral. Without distinct lunule or 
corselet. Shell rather thick. Hinge broad, with about fourteen teeth 
altogether. Pallial sinus small. Surface smooth. 
Only the figured specimen was found and no opportunity has yet been 
found to compare it with the German typical specimens. What Wood 
describes as Leda pygmiea Muenst. from the Crag§$ has been separated by 
Weinkauff || from the German species and identified with the recent Leda 
tenuis Philippi.4/ It seems to have a thinner shell and more teeth than 
the German Oligocene form. The Yorktown specimen has a solid shell 
and relatively few teeth. 
Modiolaria petagne Scacchi. Fig. 8. 
Modiola Petagnee Scacchi, Philippi, Enum. moll. Sic. Vol. ii, p. 51; 
Vol.4, P10, fig. al. 
Oblong; ventricose; angular posteriorly. Anterior side contracted, 
extending beyond the umbo. Anterior and posterior surface radiately 
ribbed, the ribs decreasing in size towards the middle and not existing on 
the middle. Whole surface moreover irregularly concentrically striated. 
The radiating ribs crenulate the inner margin. Inside somewhat nacreous. 
Both the concentric and radiating ribs are not regularly arranged, taking 
their origin by bifurcation of other ribs. By the crossing of the ribs the 
anterior and especially the posterior surface appear cancellate. 
The shell agrees with the Crag form, which Wood described as Modiola 
costulata Risso,** comparing it with the figure of Philippi in the Enume- 
ratio molluscorum Sicilie, Vol. i, p. 70, Pl. 5, fig. 11, referred by Philippi 
himself in Vol. ii, p. 51, to M. petagnee Sc. But Wood considered M. 
* Conrad, Mioc. Fossils, p. 48, Pl. 21, fig. 5. 
+ Ibid., p. 44, Pl. 21, fig. 7. I have seen specimens labeled with Conrad’s handwriting 
“« Astarte coheni,’’? but with entire margin, while he describes this species with crenu- 
lated margin, like A. symmetrica. Altogether I am not aware of any specific difference 
between the two forms, even if the margins should.differ. 
{ Gould, Invert. Mass., p. 81, fig. 48. 
2 Crag Moll., Vol. ii, p. 95, Pl. 10, fig. 11. 
| Weinkauff, Conchilien d. Mittelmeeres, Vol. i, p. 211. 
q Phil., Enum. Moll. Sic., Vol. i, p. 65, Pl. 5, fig. 9. 
#* Crag. Moll., p. 60, Pl. 8, fig. 6. 
