592 



PISCES. 



[CdvL. — COP. 



Fig. 1111.— Cochliodus 

 con tortus. 



the outer margin, convex above, con- 

 cave below, with porous grinding sur- 

 faces, as in Psaramodus, from the ter- 

 mination of the vertical medullary 

 canals. Type C. contortus. 



costatus, 

 Newbe rry 

 & Worth en, 

 1870, Geo. 

 Sur. 111., 

 vol. 4, p. 



S V, f I :;,i4 ' l> " 1 '' 



(f.-ik-^ ""■ ^<j$ i lington Gr. 



erassus, New- 

 berry & 

 Wort he n , 



« I860, syn. 



for Sandalodus hevissimus. 

 latus, see Chitonodus latus. 

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



Sur. 111., vol. 7, p. 127, Kaskaskia Gr. 

 nUidm, see Deltoptychius nitidus. 

 nobilis, Newberry & Worthen, syn. for 



Chitonodus latus. 

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



Sur. 111., vol. 7, p. 126, St. Louis Gr. 

 occidentalis, see Deltodus occidentals, 

 vanhornii, St. John &. Worthen, 1883, 

 Geo. Sur. 111., vol. 7, p. 120, St. 

 Louis Gr. 

 Coslacanthus, Agassiz, 1836, Recherches 

 sur les Poissons Fossiles, t. 2, p. 170. 

 [Kty. koilot, hollow; akantha, spine.] 

 Head plates sculptured; scales large, 

 imbricated, sculptured, arranged diag- 

 onally; two small dorsal fins supported 

 on interspinous bones, the anterior one 

 n little forward of the ventral tin, and 

 the posterior one marly opposite the 

 anal fin ; caudal fin equi-lobate, and 

 near its extremity a minute supple- 



Fig. 1112.— Coelacan thus elegans. 



mental caudal ; vertebral column carti- 

 laginous, but neural arches and fin-rays 

 bony ; teeth small, numerous, conical. 

 Type C. granulosus. 



elegans, Newberry, 

 1856, Proc. Acad. 

 Nat. Sci. Phil., vol. 

 8, p. 98, and Ohio 

 Pal., vol. 1, p. 339, 

 Coal Meas. 



ornatus, Newberry, 



1856, Proc. Acad. Fig. HIS. — Ccelacan- 

 Nat, Sci. Phil., vol. «? U8 granulosus, 

 n r.o j Vvu- Magnified scale. 



8, p. 98, and Ohio 



Pal., vol. 1, p. 340, Coal Meas. 

 robustus, Newberry, 1856, Proc. Acad. 

 Nat. Sci. Phil., vol. 8, p. 98, and Ohio 

 Pal., vol. 1, p. 341, Coal Meas. 



CoMPSACANTiius, Newberry, 1857, Proc. 

 Acad. Xat. Sci., vol. 8, p. 99, and Ohio 

 Pal., vol. 1. p. 331. [F'ty. compsos, ele- 

 gant ; akanth'i, a spine.] Spines small, 

 gently curved backward; exposed part 

 smooth, polished; section circular; 

 single row of remote, depressed hooks 

 on the posterior median line. Type C. 

 lsevis. 

 lsevis, Newberrv, 1857, Proc. Acad. Nat. 

 Sci. Phil., vol. 8, p. 99, and Ohio Pal., 

 vol. 1, p. 332, Coal Meas. 



Fig. 1114.— Com psacanthus lsevis. 



Coiichiopsis, syn for C'udacanthus. 

 angulifcrus, syn. for Ccelacanthua elegans. 

 exanthematicus, syn. lor Peplorhina an- 



thracina. 

 ftliferus, syn. for Coelacan thus elegans. 



Conchodtjs, Mc- 

 Coy, 1848, 

 Ann. and 

 Mag. Nat. 

 Hist., 2d. 

 8er., vol. 2. 

 [Ety. con- 

 chas, shell ; 

 od<ws,tooth.j 

 Teetli large, 

 somewhat semicircular, pointed in 

 front, 8ubtruncate behind, deeply con- 

 cave on the grinding surface ; internal 

 margin straight, thickened, edge ab- 

 ruptly deflected ; external border con- 

 vex, much raised, undulato-plicate, 

 ridgts larger in front, smaller poste- 

 rior; under surface polished, minutely 

 porous. Type C. ostreiformis. 



Fig. Hi)— Conchodus 

 plicatus. 



plfcatus, Dawson ; U 

 209, Coal Meas. 

 Copodus, Agassiz, MSS., 

 1859, St. John & 

 Worthen, 1883. Geo. 

 Sur. 111., vol. 7, p. 

 227. [Ety. kopis, 

 broad, curved knife; 

 odous, tooth.] Teeth 

 bilaterally sym- 

 metrical, spanning 

 the jaw without 

 mesial suture, ar- 

 ranged in single, 

 longitudinal series 

 from behind back- 

 ward ; lateral bor- 

 ders converging an- 

 teriorly ; coronal 

 region arched ; rim 

 at base ; anterior F 

 and posterior walls 

 vertical, channeled ; 

 inferior surface 



concave ; porous 

 beneath the enam- 

 eled coronal surface, 

 nutus. 



Acad. Geol., p. 



ro. 1116. — Copodus 

 cornntus. Maxil- 

 lary form, a. Trit- 

 urating surface ; 6, 

 transverse profile ; 

 c, longitudinal pro- 

 file. 



Type C. cor- 



