72 
PALEONTOLOGY OF NEW-YOKK. 
Fig. 7 a, b. Dorsal and ventral valve of a full grown specimen. 
Fig. 7 c. Profile view of the same. 
Fig. 7 d. Front view of the same, showing the three plications in the mesial sinus, and four on 
the elevation. 
Position and locality. In the upper limestone of this group at Lockport. 
(<Collection of Col." Jewett.) 
460. 31. ATRYPA RETICULARIS. 
Pl. XXIII. Fig. 8 a -e.'W - 
Anomia reticularis. Linne, 1767, Syst. Naturae, 12th ed., Vol. i, p. 1152; 1798, Encyclop. 
Metbodique, pl. 242, fig. 4 a, b, c. 
Terebratulithus priscus. Schlotheim, Petrefactae, 1820 : Nachtrage, pl. 17, fig. 2 ; pl. 20, 
fig. 4. 
— explanatus. In. Ibid. p. 263 ; Nachtrage, pl. 18, fig. 2. 
Anomites reticularis. Wahlekbeeg, 1821, Act. Soc. Sci. Upsalensis, Yol. viii, p. 65, no. 6. 
Terebratula affinis. Soweeby, 1823, Min. Conchology, Vol. iv, pag. 24, pl. 324, fig. 2. 
Atrypa reticularis. Dalman, 1827, Vet. Acad. Handlingar, pag. 127, pl. 4, fig. 2. 
Terebratula cancellata. Eichwald, 1829, Zool. sp., Vol. i, pag. 276, pl. 4, fig. 11. 
Porambonites maxima. Pander, 1830, Beitr. zur Geogn. Russland, pl. 16 B, fig. 7. 
Terebratula prisca. Lamarck, 1836, Anim. sans Vertebres, 2d edit., Vol. vii, p.365. 
— reticularis. Broke, 1837, Leth. Geognostica, page 72, pl. 2, fig. 10. 
— prisca. Pusch, 1838, Polen’s Palaeontologie, p. 26. 
— — Von Buch, 1838, Mem. Soc. Geol. de France, Vol. iii, pl. 16, fig. 19. 
Atrypa affinis. J. Sowerby, 1839, in Murchison’s Sil. System, pl. 6, fig. 5. 
— aspera. Id. 1839, in Sil. System, pl. 12, fig. 5. 
— reticularis. Hisinger, 1839, Leth. Suecica, pag. 75, pl. 21, fig. 11 a, b, c, d, e 
Terebratula prisca. Von Buch, 1840, Beitr. zur Geog. Russland. 
— — J. Sowerby, 1840, Geol. Transactions, 2d series, Vol. v, p. 703. 
Atrypa aspera. Id. Ibid. pl. 56, fig. 23. 
Terebratula prisca. Eichwald, 1840, Sil. Syst. in Esthl., p. 141. 
— armiger. Id. apud Von Buch, 1840, Beitr. zur geog. Russland, p. 108. 
Atrypa prisca. Phillips, 1841, Pal. Fossils, pl. 33, fig. 145. 
— affinis. Vanuxem, Geol. Rep. 3d Dist. N. York, 1842, p. 88. 
— — Hall, Geol. Rep. 4th District, 1843, p. 108. 
Terebratula reticularis. De Verneuil, Geol. Russia and the Ural Mts., 1845, p. 9, pl. x, fig. 
12 a, b, c. 
Shell subrotund, more or less compressed, subtruncated above or on the hinge-line ; valves 
more or less equal, the beak of the dorsal valve extending beyond the ventral valve, and the 
latter being deeper and more convex in older specimens ; surface marked by dichotomous 
rounded striae, which are crossed by concentric elevated lamellae, giving a reticulated or de¬ 
cussated character to the surface. 
It is impossible to give a definite description of this very protean species, which commences 
its existence in the Clinton group, and continues under various modifications through the suc¬ 
ceeding strata as far as the Chemung group. In each of its geological positions, however, it 
presents peculiar characters, and we are able to decide at once the geological position of spe¬ 
cimens, by these peculiarities. 
