THO. — VEN.] 



PISCES. 



613 



Fig. 



1176.— Tan aod us 

 cillimus. 



bellicinctus, St. John & Worthen, 1875, 

 Geo. Sur. 111., vol. 6, p. 376, Kaskas- 

 kia Gr. 



depressus, St. John & Worthen, 1875, 

 Geo. Sur. 111., vol. 6. p. 378, Kaskas- 

 kia Gr. 



gracillimus, 

 Newberry & 

 Worthen, 

 1866, (Choma- 

 todus gracilli- 

 mus,) Geo. 

 Sur. 111., vol. 

 2, p. 51, Burlington Gr. 



grossiplicatus, St. John & Worthen, 1875, 

 Geo. Sur. 111., vol. 6, p. 375, Kaskas- 

 kia Gr. 



multiplicatus, Newberry & Worthen, 

 1866, (Chomatodus multiplicatus,) Geo. 

 Sur. 111., vol. 2, p. 57, Burlington Gr. 



obscurus, Leidy, 1856, (Chomatodus ob- 

 scurus,) Trans. Am. Phil. Soc, vol. 11, 

 p. 87, Keokuk Gr. 



polymorphus, St. John & Worthen, 1875, 

 Geo. Sur. 111., vol. 6, p. 380, Kaskas- 

 kia Gr. 



prsenuntius, St. John & Worthen, 1875, 

 Geo. Sur. 111., vol. 6, p. 371, St. Louis Gr. 



pumilus, St. John & Worthen, 1875, Geo. 

 Sur. 111., vol. 6, p. 369, St. Louis Gr. 



sculptus, St. John & Worthen, 1875, Geo. 

 Sur. 111., vol. 6, p. 373, St. Louis Gr. 



sublunatus, St. John & Worthen, 1875, 

 Geo. Sur. 111., vol. 6, p. 368, St. 

 Louis Gr. 

 Thobacodus, Cope, 1883, Proc. Acad. Nat. 

 Sci., p. 108. [Ety. thoracos, protected; 

 odous, tooth.] Jaws plate-like, divided 

 on middle line, each half with trans- 

 verse grooves and ridges, and a smooth 

 border all round. Type T. eurydinus. 



eurydinus, Cope, 1883, Proc. Acad. Nat. 

 Sci. Phil., p. 108, Permian Gr. 

 Thbinacodus, St. John & Worthen, 1875, 

 Geo. Sur. 111., vol. 6, p. 289. [Ety. 

 thrinakos, three-pronged; odous, tooth.] 

 Teeth small ; base produced posteriorly 

 in a long sometimes twisted vertically 

 flattened, or laterally compressed, cla- 

 vate plate, longer than wide, anterior 

 face narrow, and abruptly beveled from 

 the basal line of the crown ; posterior 

 extremity more or less obtusely rounded; 

 inferior surface narrow, plain or faintly 

 excavated ; superior surface gently 

 convex, concave antero-posteriorly, or 

 corresponding to the curvature of the 

 inferior surface ; from the antero-supe- 

 rior extremity of the base spring three 

 more or less relatively stout, nearly 

 equal, trenchant, acutely pointed, re- 

 curved cusps the exterior pair diver- 

 gent, the central one more or less verti- 

 cal, slightly sigmoidally curved, trans- 

 verse section sublenticular, compressed 

 in front, rounded behind, with simple 

 cutting edges, and more or less strongly 

 costate in either face. Allied to Diplo- 

 dus. Type T. nanus. 



duplicatus, Newberry & Worthen, 1866, 

 (Diplodus duplicatus,) Geo. Sur. Ill,, 

 vol. 2, p. 61, Keokuk Gr. 



incurvus, Newberry & Worthen, 1866, 

 (Diplodus incurvus,) Geo. Sur. 111., 

 vol. 2, p. 62, Keokuk Gr. 



nanus, St. John & Worthen, 1875, Geo. 

 Sur. 111., vol. 6, p. 289, Waverly or Kin- 

 derhook Gr. 

 Tomodus, Agassiz, 1859, MSS. and St. John 

 & Worthen, 1883, Geo. Sur. 111., vol. 7, 

 p. 171. [Ety. tomos, sharp ; odous, 

 tooth.] Distinguished from Xystrodus 

 by the great convexity of the coronal 

 ridge, abrupt articular border, and ab- 

 sence of transverse punctse on the trit- 

 urating surface. Type T. convexus. 



limitaris, St. John & Worthen, 1883, Geo. 

 Sur. 111., vol. 7, p. ,173, Upper Burling- 

 ton Gr. 

 THgonodus, Newberry & Worthen, 1866, 

 Geo. Sur. 111., vol. 2, p. 111. [Ety. trig- 

 onos, three-cornered ; odou*, tooth.] Syn. 

 for sandalodus. 



major, Newberry & Worthen, 1866, Geo. 

 Sur. 111., vol. 2, p. 112, syn. for Sanda- 

 lodus complanatus. 



minor, see Sandalodus minor. 

 Vaticinodus, St. John & Worthen, 1883, 

 Geo. Sur. 111., vol. 7, p. 80. [Ety. vati- 

 cinus, prophetical ; odous, tooth.] Pos- 

 terior teeth distinguished from Deltop- 

 tychiusby the absence of the secondary 

 lobe, the anterior part of the tooth for- 

 ward of the posterior prominence being 

 plain, as in Stenopterodus. Type V. 

 vetustus. 



carbonarius, St. John & Worthen, 

 1883, Geo. Sur. 111., vol. 7, p. 88, Coal 

 Meas. 



discrepans, St. John & Worthen, 1883, Geo. 

 Sur. 111., vol. 7, p. 83, Upper Burling- 

 ton Gr. 



lepis, St. John & Worthen, 1883, Geo. Sur. 

 111., vol. 7, p. 88, Up. Coal Meas. 



similis, St. John & Worthen, 1883, 

 Geo. Sur. 111., vol. 7, p. 86, Kaskas- 

 kia Gr. 



simplex, St. John & Worthen, 1883, Geo. 

 Sur. 111., vol. 7, p. 84, St. Louis Gr. 



vetustus, St. John & Worthen, 1883, Geo. 

 Sur. 111., vol. 7, p. 82, Waverly or Kin- 

 derhook Gr. 

 Venustodus, St. John & Worthen, 1875, 

 Geo. Sur. 111., vol. 6, p. 344. [Ety. ve- 

 nustus, beautiful ; odous, tooth.] Teeth 

 laterally elongated, vertically arched ; 

 crown constricted at the base, defined 

 by imbricating folds; crest elevated, 

 uniform, or with median prominence ; 

 denticulations lateral ; base forming a 

 shallow plate. Type V. robustus. 



argutus, St. John & Worthen, 1875, 

 Geo. Sur. 111., vol. 6, p. 352, Kaskas- 

 kia Gr. 



leidyi, St. John & Worthen, 1875, Geo. 

 Sur. 111., vol. 6, p. 350, St. Louis Gr. 

 This name is a syn. for V. venustus. 



40 



