PHY. — TRA.J 



PISCES. 



Ill 



Physonemus altonensis, see Stethacanthus 

 altonensis. 



stellatus, Newberry, 1889, Pal. Fish N. 

 Am., p. 200, St. Louis Gr. 

 Ponerichthys, n. gen. [Ety. poneros, 

 wicked ; ichthys, a fish.] Proposed for 

 Dinichthys, Newberry, 1873, Ohio Pal., 

 vol. 1, p. 313, and yol. 2, p. 3, which 

 was preoccupied among the fishes by 

 Hitchcock, in 1868. Type P. terrelli. 



eorrugatus, P. curtus, P. gouldi, P. inter- 

 medins, P. minor, Newberry, 1889, Pal. 

 Fish N. Am., pp. 149 to 156, Cleveland 

 Shale. 



hertzeri, Newberry, 1873, (Dinichthys 

 hertzeri,) Ohio Pal., vol. 1, p. 316, Por- 

 tage Gr. 



precursor, Newberry, 1889, Pal. Fish N. 

 Am., p. 51, Corniferous Gr. 



terrelli, Newberry, 1873, (Dinichthys ter- 

 relli,) Ohio Pal., vol. 1, p. 313, and vol. 

 2, p. 3, Portage Gr. 



tuberculatus, Newberry, 1889, Pal. Foss. 



N. Am., p. 98, Chemung Gr. 



Pristicladodus is said to be a synonym for 



Dicrenodus, by Woodward & Sherborn. 



Pristodus, Agassiz, MSS. only, Davis, 1883, 



Trans. Roy. Soc. Dub., vol. 1, p. 519. 

 Protodus, Woodward, 1892, Lond. Geo. 

 Mag., vol. 9, p. 1. [Ety. protos, first ; 

 odous, tooth.] A Selachian tooth ; dental 

 crown consists of a single robust, solid, 

 conical cusp, invested with gano-den- 

 tine ; root large, undivided, laterally 

 expanded and antero-posteriorly com- 

 pressed. Type P. jexi, described at the 

 same place from the Low. Devonian. 



Pterichthys was preoccupied by Swainson 

 among the fishes in 1839. See Miller- 

 ichthys. 



rugosus, see Holonema rugosum. 

 Rhizodus anceps, Newberry, 1889, Pal. 



Fish N. Am., p. 191, St. Louis Gr. 

 Rhynchodus greenei, Newberry, 1889, Pal. 



Fish N. Am., p. 51, Ham. Gr. 

 Sphenophorus, Newberry, 1889, Pal. Fish N. 

 Am., p.' 92. The name was preoccupied 

 among the Coleoptera, by Schoenherr, 

 in 1838. See Oestophorus. 

 Stethacanthus, Newberry, 1889, Pal. Fish 

 N. Am., p. 198. [Ety. slethos, the breast; 

 akantha, a spine.] Pectoral spines of 

 medium or large size, unsymmetrical, 

 (rights and lefts,) broadly falcate in 

 outline, the conical summit compressed, 

 with anterior and posterior margins 

 rounded; below the solid summit the 

 posterior margin is opened by a deep 

 sulcus, of which the walls, of unequal 

 thickness, terminate posteriorly in thin 

 and fragile edges ; anterior border gen- 

 tly concave, about one third its length 

 from the base rising into a strong, often 

 tumid, shoulder; basal portion narrow 

 and compressed, terminating in a car- 

 tilaginous condyle for articulation. In 

 life the posterior sulcus was occupied 

 by the base of the pectoral fin. Type 

 S. altonensis. 



altonensis, St. John & Worthen, 1875, 

 (Physonemus altonensis,) Geo. Sur. 

 III., vol. 6, p. 454, St. Louis Gr. 

 tumidus, Newberry, 1889, Pal. Fish N. 

 Am., p. 198, Berea Grit. 



Tegeolepis, n. gen. [Ety. tegeos, a roof ; 

 lepis, scale.] Proposed for Actinophorus, 

 Newberry, 1889, Pal. Fish N. Am., p. 

 174, which was preoccupied among the 

 Coleoptera, by Creutz, in 1799. Tile- 

 scaled ganoids, of medium or large 

 size, long and slender ; body cylindrical ; 

 head pointed, bony ; teeth numerous, 

 conical, acute ; fins without fulcra, deli- 

 cate, many- rayed; scales narrow, quad- 

 rangular, thin. Type T. clarkii. 

 clarkii, Newberry, 1889, (Actinophorus 

 clarkii,) Pal. Fish N. Am., p. 175, Cleve- 

 land Shale. 



Titanichthys, Newberry, 1889, Pal. Fish 

 N. Am., p. 130. [Ety. mythological 

 name ; ichthys, a fish.] Cranium of 

 more gigantic size than that of Poner- 

 icbthys, being about 4 feet broad at the 

 occiput, 3 feet or more in length, trian- 

 gular in outline, and marked by incised 

 lines; supra scapulas or supra-clavicles 

 rhomboidal or trapezoidal in outline, 

 from 15 to 20 inches in diameter; 

 clavicles 2 feet in length by eight inches 

 in breadth, turned forward and nar- 

 rowed at the lower end ; mandibles 2 or 

 3 feet in length, subcylindrical or sub- 

 triangular rods curved upward ante- 

 riorily and furrowed like a gouge. Type 

 T. agassizi, which, with T. clarkii, is de- 

 scribed at the same place from the 

 Cleveland Shale. 



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



Worthen, 1883, Geo. Sur. 111., vol/7, p. 



171. was preoccupied among the fishes 



by Trautschold, in 1879. See Icanodus. 



limitaris, see Icanodus limitaris. 



Trachosteus, Newberry, 1889, Pal. Fish N. 

 Am., p. 166. [Ety. trachys,- rough ; osteon, 

 a bone.] Placoderm fishes inclosed in 

 defensive armor, consisting of a number 

 of large, but relatively thin, bony 

 plates, of which the outer enameled 

 surface is thickly set with high conical 

 tubercles, that are acute, rounded, or. 

 cupped at the summit ; the spaces be- 

 tween these tubercles are radiately 

 lined ; under jaws consisted of cartilagi- 

 nous, angular, and articular parts with 

 dense bony dentary portions ; dental 

 bones straight, posterior end spatulate, 

 anterior third or exposed part carries a 

 row of slender, conical, acute teeth 

 along its upper margin ; premaxillaries 

 subtriangular in outline, anteiior face 

 arched, and terminating below in an 

 acute point; posterior edge horizontal, 

 and carrying slender, pointed teeth, 

 which matched with a portion of those 

 of the mandible ; eye orbits relatively 

 large and round, encircled by a ring 

 composed of four sclerotic plates, those 

 on one side narrower than the others ; 



