TRK. — TSO.] 



CEPHALOPODA. 



455 



hole; keras, horn.] Shell straight, ob- 

 conical, like Orthroceras as to tube, 

 septa, and siphuncle ; characterized by 

 a line of elongated, raised tubercles 

 along one side of the shell, which at one 

 stage of growth formed perforations, 

 which were closed as the animal ex- 

 tended the shell. Type T. ohioense. 



ohioense, Whitfield, 1882, Ann. N. Y. 

 Acad. Sci., vol. 2, p. 206, Up. Held. Gr. 

 Tbematodisccjs, Meek & Worthen, 1861, 

 Proc. Acad. Nat. Sci. Phil., p. 147. [Ety. 

 trema, hole ; diskos, quoit.] Discoid, 

 wide, shallow, umbilicus, perforated in 

 the middle, showing all the whorls ; 

 whorls slender, merely in contact pos- 

 sessed of revolving angles, grooves, or 

 stride; siphuncle central or subcentral 

 on the dorsal side. Type T. stygialis. 

 The name having been used in I860 by 

 Haeckel for Radiolaria, Hyatt proposed 

 Trematoceras. 



altidorsalis, Winchell, 1862, Proc. Acad. 

 Nat. Sci., p. 429, Marshall Gr. 



digonus, Meek & Worthen, 1860, (Nau- 

 tilus digonus,) Proc. Acad. Nat. Sci., p. 

 470, and Geo. Sur. 111., vol. 2, p. 163, 

 Kinderhook Gr. 



discoidalis, Winchell, 1862, Am. Jour. 

 Sci., vol. 33, 2d series, p. 360, Mar. 

 shall Gr. 



konincki, Wetherby, 1881, Jour. Cin. Soc. 

 Nat. Hist., vol. 4, p. 79, Waverly Gr. 



Fig. 762. -Trematodiscus konincki. 



meekanus, Winchell, 1862, Am. Jour. 

 Sci., 2d series, vol. 33, p. 360, Mar- 

 shall Gr. 



planidorsalis, Winchell, 1862. Am. Jour. 

 Sci., 2d series, vol. 33, p. 358, Mar- 

 shall Gr. 



rockymontanus, S. A. Miller, 1881, Jour. 

 Cin. Soc. Nat. Hist., vol. 4, p. 312, Bur- 

 lington Gr. 



striatulus, Winchell, 1862, Proc. Acad. 

 Nat. Sci., 2d series, vol. 33, p. 358, Mar- 

 shall Gr. 



strigatus, Winchell, 1862, Proc. Acad. Nat. 

 Sci., p. 426, Marshall Gr. 



sulcatus, Meek & Worthen, 1866, Proc. 

 Acad. Nat. Sci. Phil., p. 274, Kaskas- 

 kia Gr. 



trieonus, Winchell, 1862, Am. Jour. Sci., 

 2d series, vol. 33, p. 358, Marshall Gr. 



trisulcatus, Meek & Worthen, 1860, Proc. 

 Acad. Nat. Sci. Phil., p. 470, and Geo. 

 Sur. 111., vol. 2, p. 162, Kinderhook Gr. 

 Trochocebas, Hall, 1852, Pal. N. Y., vol. 2, 

 p. 335. [Ety. trochos, hoop ; keras, horn.] 

 This name was proposed by Barrande 

 at about the same time. Turbinate or 

 trochiform, spire elevated, more or less 

 ventricose ; umbilicated ; aperture 

 rounded or round oval ; volutions above 

 the outer one septate ; siphuncle sub- 

 marginal or dorsal. Type T. gebhardi. 



seneas, Hall, 1870, Rev. Ed. 20th Rep. 

 N. Y. Mus. Nat. Hist. Expl., pi. 25, 

 Niagara Gr. 



baeri, see Gyroceras baeri. 



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

 p. 398, Schoharie grit. 



biton, Hall, 1879, Pal. N. Y., vol. 5, p. 395, 

 Schoharie grit. 



clio, Hall, 1861, 14th Rep. N. Y. Mus. 

 Nat. Hist., p. 108, Schoharie grit. Type 

 of Hyatt's genus Sphyradoceras. 



costatum, Hall, 1861, Geo. Rep. of Wis., 

 Niagara Gr. 



desplainense, McChesney, 1860, New Pal. 

 Foss., p. 68, Niagara Gr. 



discoideum, Hall, 1862, 15th Rep. N. Y. 

 Mus. Nat. Hist., p. 64, and Illust. De- 

 von. Foss., pi. 59, Schoharie grit. 



eugenium, Hall, 1861, 14th Rep. N. Y. 

 Mus. Nat. Hist., p. 108, Schoharie grit. 

 Type of Hyatt's genus Naedoceras. 



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

 p. 402, Schoharie grit. 



gebhardi, Hall, 1852, Pal. N. Y., vol. 2, 

 p. 335, Coralline Gr. 



incipiens, Barrande, 1869, Syst. Sil. de 

 Boh., 4me ser., Quebec Gr. 



notum, Hall, 1867, 20th Rep. N. Y. Mus. 

 Nat. Hist., p. 403, Niagara Gr. 



obliquatum, Hall, 1876, Illust. Devonian 

 Foss., pi. 48, Up. Held. Gr. 



orion, Hall, 1876, (Cyrtoceras orion,) Il- 

 lust. Devonian Foss., pi. 48, Up. Held. Gr. 



pandion, Hall, 

 1876, Illust. De- 

 vonian Foss., 

 pi. 48, and Pal. 

 N. Y., vol. 5, pt. 

 2, p. 400, Scho- 

 harie grit. 



pandum, Hall, 

 1879, Pal. N.Y., 

 vol. 5, p. 403, 

 Schoharie grit. 



turbinatum, Hall, 

 1852, Pal. N.Y., 

 vol. 2, p. 336, 

 Coralline Gr. 



waldronense, FlG " 763.-Trochoceras wal- 

 Hall, 1876, 28th dronense. 



Rep. N. Y. Mus. Nat. Hist., p. 179, Ni- 

 agara Gr. 



