392 



PTEROPODA. 



[MAT. STY. 



FIG. 647. Matthevia 

 variabilis. 



striatus, Hall, 1876, lllust. Devonian Foss., 

 pi. 27, and Pal. N. Y., vol. 5, pt. 2, p. 

 199, Ham. Gr. 



subimbricatus, Ringueberg, 1888, Proc. 

 Acacl. Nat. Sci. Phil., p. 135, Niag- 

 ara Gr. 

 triliratus, Hall, 1879, Pal. N. Y., vol. 5, 



pt. 2, p. 201, Ham. Gr. 

 vanuxemi, Walcott, 1885, Monogr. U. 8. 



Geo. Sur., vol. 8, p. 85, Chazy Gr. 

 MATTHEVIA, Walcott, 1885, Am. Jour. Sci. 

 and Arts, 3d ser., vol. 30, p. 17. [Ety. 

 proper name.] Shell conical ; aperture 

 sinuous, transverse section, ovate, el- 

 liptical or rounded subquadrate; two 

 elongate interior chambers, diverging 

 from the apex, open into the terminal 

 chamber, and are crossed by a single 

 imperforate sep- 

 tum; surface pa- 

 pillose ; opercu- 

 lum calcareous, 

 nucleus excentric, 

 lines of growth 

 concentric. Type 

 M. variabilis. 

 variabilis, Walcott, 

 1885, Am. Jour. 

 Sci. and Arts, 3d 

 ser., vol. 30, p 18, Calciferous Gr. 

 PHABETRELLA, Hall, 1888, Pal. N. Y., vol. 7, 

 p. 7. Shell large, elongate, Hyolithes- 

 like in outline ; apex acute ; surface or- 

 namented with transverse, undulating 

 striae. Type P. tenebrosa. 

 tenebrosa, Hall, 1888, Pal. N. Y., vol. 7, p. 



7, Genesee Slate. 



PTEROTHECA, Salter, 1852, Rep. Brit. Ass'n, 

 p. 61. [Ety. pteron, wing ; The ca, a genus.] 

 Shells arcuate, somewhat calyptrseform, 

 subtriangular, or oval ; apex marginal 

 and incurved on the same plane, cari- 

 nate upon the back, abruptly and 

 broadly expanding, with the anterior 

 margin sinuate ; interior concave, shal- 

 low ; a concave, shelly partition covers 

 the posterior half of the cavity. Type 

 P. transyersa. 



anatiformis, Hall, 1847, (Tellinomya anat- 

 iformis,) Pal. N. Y., vol. 1, p. 154, Tren- 

 ton Gr. 



attenuata, Hall, 1861, (Clioderma attenu- 

 ata,) 14th Rep. N. Y. St. Mus. Nat. Hist., 

 p. 98, Trenton Gr. 



canaliculata, Hall, 1861, (Cleioderma ca- 

 naliculata,) 14th Rep. N. Y. St. Mus. 

 Nat. Hist., p. 97, Trenton Gr. 

 expansa, Emmons, 1842, (Delthyris ex- 

 pansus,) Geo. Rep. N. Y., p. 397, Black 

 Riv. and Trenton Grs. 

 saffordi, Hall, 1861, (Cleioderma saffordi,) 

 14th Rep. N. Y. St. Mus. Nat. Hist., p. 

 96, Trenton Gr. 

 transverse, Salter, 1852, Rep. Brit. Ass'n, 



p. 61, Hud. Riv. Gr. 



undulata, Hall, 1861, (Cleioderma undu- 

 lata,) 14th Rep. N. Y. St. Mus. Nat. 

 Hist., p. 97, Trenton Gr. 



Pugiunculus aculeatus, see Hyolithes acu- 

 leatus. 



SCENELLA, Billings, 1872, Can. Nat. and 

 Geol., vol. 6, p. 479, and Pal. Foss., vol. 

 2, p. 77. [Ety. scene, tent ; ella, diminu- 

 tive.] Shell small, depressed, conical ; 

 apex central, an obscure carina extend- 

 ing from the apex to the margin ; apex 

 slightly incurved opposite the carina ; 

 aperture nearly circular; surface finely 

 reticulated. Type S. reticulata. 



conica, Whiteaves, 



1884, Pal. Foss., 

 vol. 3, p. 32, 

 Guelph Gr. 



conula, Walcott, 1885, *io 648. Scenella con- 

 Monogr. U. S. Geo. lca - Side view - 

 Sur., vol. 8, p. 15, Up. Taconic. 



reticulata, Billings, 1872, Can. Nat. and 

 Geo., vol. 6, p. 479, and Pal. Foss., vol. 

 2, p. 77, Up. Taconic. 



retusa, Ford, 1873, Am. Jour. Sci. and 

 Arts, 3d series, vol. 5, p. 213, Up. 

 Taconic. 



varians, Walcott, 1886, Bull. U. S. Geo. 



Sur., vol. 30, p. 127, Up. Taconic. 

 STENOTHECA, Hicks, 1872, Quar. Jour. Geo. 

 Soc., vol. 28, p. 180. [Ety. stenos, nar- 

 row; Theca, genus.] Shell small, curved; 

 lines of growth strongly marked trans- 

 versely. Type S. cornucopia. 



acadica, Hartt, 1868, (Discina acadica,) 

 Acad. Geol., p. 644, St. John Gr. 



concentrica, Matthew, 1885, Trans. Roy. 

 Soc. Can., p. 57, St. John Gr. 



elongata, Walcott, 1885, Monogr. U. S. 

 Geo. Sur., vol. 8, p. 23, Up. Taconic. 



hicksana, Matthew, 1885, Trans. Roy. Soc. 

 Can., p. 56, St. John Gr. 



nasuta, Matthew, 1885, Trans. Roy. Soc. 

 Can., p. 58, and Can. Nat. and Geo., vol. 

 6, p. 479, St. John Gr. 



pauper, Billings, 1872, Pal. Foss., vol. 2, 

 p. 77, Up. Taconic. 



radiata, Matthew, 1885, Trans. Roy. Soc. 

 Can., p. 57, St. John 



jjgfr rugo^, Hall, 1847, (Me- 



"* toptoma rugosa, Pal. 



N. Y., vol. 1, p. 306, 

 Up. Taconic. 

 triangularis, Matthew, 



1885, Trans. Roy. Soc. Can., p. 58, St. 

 John Gr. 



STYI.IOLA, Lesueur, 1826. [Ety. stylos, pillar.] 

 Small, conical, without annulations 

 which distinguishes it from Tentac- 

 ulites. 



fissurella, Hall, 1843, (Tentaculites fissurel- 

 lus,) Geo. 4th Dist. N. Y., p. 180, and 

 Pal. N. Y., vol. 5, pt. 2, p. 178, Marcel- 

 lus Shale and Genesee Slate. 



fissurella var. intermittens, Hall, 1879, 

 Pal. N. Y., vol. 5, pt. 2, p. 181, Gen- 

 esee Slate. 



fissurella var. obsolescens, Hall, 1879, 

 Pal. N. Y., vol. 5, pt. 2, p. 180, Ham. Gr. 



fissurella var. strigata, Hall, 1879, Pal. N.Y., 

 vol. 5, pt. 2, p. 180, Marcellus Shale. 



Fio. 649.-Stenoth- 

 eca ragosa. 



