GON. — GYR.] 



CEPHALOPODA. 



441 



Gonioceras, Hall, 1847, Pal. N. Y., vol. 1, 

 p. 54. [Ely. gonia, angle; keras, horn.] 

 Somewhat in the form of an Orthoceras, 

 but more or less flattened and subfusi- 

 form; transverse section in the form of 

 a depressed ellipse with projecting 

 angles; siphuncle ventral, septa curve 

 over the ventral side, as shown in the 

 illustration. Type G. anceps. 



Fig. 742.— Gonioceras anceps. 



anceps, Hall, 1847, Pal. N. Y., vol. 1, p. 

 54, Black Riv. Gr. 



occidental, Hall, 1861, Rep. of Progr.Wis., 

 p. 47, Trenton Gr. 

 Gyroceras, DeKoninck, 1844, Desc. An. 

 Foss. Belg., p. 530. [Ety. gyros, circle; 

 keras, horn.] Not Gyroceratites of 

 Meyer, 1829. Discoid, rolled in one 

 plane; volutions in contact or open, 

 but not embracing ; transverse section 

 circular, elliptical, scutiform, or polyg- 

 onal ; body chamber large and some- 

 times straight or tangent to the spiral ; 

 opening hollowed out on the exterior 

 border like the Nautilus ; septa arched 

 and frequently project, curving back- 

 ward ; siphon slender, cylindrical, and 

 usually subcentral toward the convex 

 border, but sometimes found within 

 the concave border ; surface tubercu- 

 lous, having imbricated excrescences or 

 ringed with projecting fringes from the 

 septa. Type G. paradoxicum. 



abruptum, Hall, 1879, Desc. New Spec. 

 Foss., p. 19, and 11th Rep. Geo. and 

 Nat. Hist., Ind. p. 325, Niagara Gr. 



americanum, Billings, 1857, Rep. of Progr. 

 Can. Geo. Sur., p. 309, Up. Sil. 



baeri, Meek & Worthen, 1865, (Trochoce- 

 ras baeri,) Proc. Acad. Nat. Sci., p. 263, 

 and Ohio Pal., vol. 1, p. 157, Hud. 

 Riv. Gr. 



bannisteri, Winchell & Marcy, 1865, Mem. 

 Bost. Soc. Nat. Hist., vol. 1, p. 102, Ni- 

 agara Gr. 



&wWwi0fonense,seeNautilusburlingtonensis. 



columbiense, Whitfield, 1882, Ann. N. Y. 

 Acad. Sci., vol. 2, p. 210, Up. Held. Gr. 



constrictum, Meek& Worthen, 1868, Geo. 

 Sur. 111., vol. 3, p. 446, Ham. Gr. 



cornutum, Owen, 1840, Rep. on Min. 

 Lands, p. 69, Devonian. 



cyclops, Hall, 1862, 15th Rep. N. Y. Mus. 

 Nat. Hist., p. 68, and Ulust. Devon. 

 Foss., pi. 53, Up. Held. Gr. 



duplicostatum, Whitfield, 1878, Ann. Rep. 

 Geo. Sur. Wis., p. 78, and Geo. Wis., 

 vol. 4, p. 235, Trenton Gr. 



elrodi, White, 1882, 11th Ann. Rep. Geol. 



and Nat. Hist. Indiana, p. 356, Niagara Gr. 

 eryx, Hall, 1862, 15th Rep. N. Y. Mus. 



Nat. Hist., p. 67, Ham. Gr. 

 expansum, Saeman, Dunker & Von Meyer, 



1853, Palseontographica, vol. 4. See 



Nautilus buccinum. 

 gracile, Hall, 1860, 13th Rep. N. Y. Mus. 



Nat. Hist., p. 105, Kinderkook Gr. 



Probably a syn. for Trematodiscus 



digonus. 

 harlti, see Discites hartti. 

 inelegans, Meek, 1871, Proc. Acad. Nat. 



Sci. Phil., p. 89, and Ohio Pal., vol. 1, 



p. 232, Up. Held. Gr. 

 jason, Hall, 1862, (Cyrtoceras jason,) 15th 



Rep. N. Y. Mus. Nat. Hist., p. 71, Up. 



Held. Gr. Type of Hyatt's genus Ru- 



tOCf 1*3,8 



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



p. 376, Up Held. Gr. 

 liratum, see Nautilus liratus. 

 logani, Meek, 1868, Trans. Chi. Acad. Sci., 



p. 110, Devonian. 

 magnificum, see Lituites magnificus. 

 matheri, Conrad, 1810, Ann. Rep. N. Y., 



p. 206, and Pal. N. Y., vol. 5, pt. 2, p. 



377, (Cyrtoceras matheri,) Up. Held. Gr. 

 nais, see Porcellia nais. 

 nereus, Hall, 1862, 15th Rep. N. Y. Mus. 



Nat, Hist., p. 67, and Pal. N. Y., vol. 5, 



pt. 2, p. 373, Up. Held. Gr. 

 numa, Billings, 1875, Can. Nat. and Geol., 



vol. 7, p. 238, Up. Held. Gr. 

 ohioense, Meek, 1871, Proc. Acad. Nat. 



Sci. Phil., p. 87, and Ohio Pal., vol. 1, 



p. 230, Up. Held. Gr. 

 paucinodum, Hall, 1876, Ulust. Devonian 



Foss., pi. 55, and Pal. N. Y., vol. 5, pt. 



2, p. 380, Up. Held. Gr. 

 pratti, Barris, 1879, Proc. Dav. Acad. Sci., 



vol. 2, p. 287, Up. Held. Gr. 

 rhombolineare, Owen, 1862, Geo. Sur. 



Indiana, p. 362, Silurian, 

 rockfordense, Meek & Worthen, 1866, 



(Nautilus (Cryptoceras) rockfordensis,) 



Proc. Acad. Nat. Sci. Phil., p. 275, and 



Geo. Sur. 111., vol. 3, p. 459, Kinder- 

 hook Gr. 

 seminodosum, Whitfield, 1882, Ann. N. Y. 



Acad. Sci., vol. 2, p. 211, Up. Held. Gr. 

 spinosum, Conrad, 1840, (Phragmoceras 



spinosum,) Ann. Rep. N. Y., p. 206, 



and Pal. N. Y., vol. 5, pt. 2, p. 382, 



Schoharie grit, 

 stebos, Beecher, 1888, Pal. N. Y., vol. 7, p. 



36, Waverly Gr. 

 subliratum, see Nautilus subliratus. 

 transversum, Hall, 1860, (Cyrtoceras 



transversum,) 13th Rep. N. Y. Mus. 



Nat. Hist., p. 104, and Pal. N. Y., vol. 



5, pt. 2, p. 384, Ham. Gr. 

 trivolve, Conrad, 1840, (Cyrtoceras tri- 



volvis,) Ann. Rep. N. Y., p. 206, and Pal. 



N. Y., vol. 5, pt 2, p. 374, Up. Held. Gr. 

 undulatum, Vanuxem, 1842, (Cyrtoceras 



undulatum,) Geo. Rep. N. Y., p. 139, and 



Pal. N. Y., vol. 5, pt. 2, p. 378, Up. Held. 



Gr. Type of Hyatt's genus Halloceras. 



