42 



PISCES 



CLASS I 



Ci/clohatis, Egerton. Disk circular or oval, and tail very short, without 

 median fins. Rays of paired fins few and well-spaced, the pectorals united in 

 front of the head. Pelvic arch with very large pre-pubic processes. C. oligo- 

 dadylus, Egerton, from Upper Cretaceous, Hakel and Hajoula, Mount Lebanon. 



Baja, Cuv. {Adinobatis, Ag.), (Fig. 2). Upper Cretaceous (Mount Lebanon) 

 to Recent. Dermal tubercles of existing B. davata, Linn., in Pliocene Crags 

 of Norfolk and SufFolk. 



Family 10. Torpedinidae. Müller and Henle. Torpedoes. 



Trunk much depressed, forming a broad and rounded disk with the pedoral fins, 

 which do not extend forwards to the broadly rounded anterior end of the head. Tail 

 short and fteshy, with well-developed dorsal and caudal fins. Skin naked. An 

 eledric organ between the pedoral fins and the head. Eocene to Recent. 



Torpedo, Dum^ril (Narcobatis, Blv.). Sometimes supposed to be represented 

 by skeletons in Upper Eocene of Monte Bolca, but doubtful. Recent. 

 Narcine, Henle. Upper Eocene of Monte Bolca, and Recent. 



Family 11. Trygonidae. Müller and Henle. Sting-rays. 



Trunk much depressed, forming a disk with the very broad pedoral fins, ivhich 

 meet in front of the snout, and constitute the anterior horder of the head. Tail very 

 slender, sharply separated from the disk, the dorsal fins usually replaced by several 

 stout imbrirating spines of vasodentine, which are antero-posteriorly compressed and 

 armed with a row of recurved hooklets on each lateral border. Teeth small, rhombic 

 or polygonal, with bifurcated root, and forming a dose pavement. Skin naked, with 

 large conical plates of vasodentine, sometimes fused into groups, usually raised into a 

 short spine. Tertiary and Recent. 



Trygon, Adanson (Trygonohatus, Blv. ; Alexandrinum, Molin), (Figs. 83, 84). 

 Tail elongated, with long, flattened dorsal spines. Dermal plates of very 

 ^ ^ ^ variable form and size. T. gazolae, Ag. ; 2\ 



(Alexandrinum) molini, Zigno ; T. zignoi, Molin, 

 known by nearly complete skeletons from the 

 Upper Eocene of Monte 

 Bolca. Isolated dermal 

 plates (Fig. 84) have 

 been described as refer- 

 able to Raja, Acipenser, 

 Dynatobatis, Larrazet, 



Fig. 83. 

 Trygon rugostis, Probst. 



Tooth, an- 

 terior (A), posterior (B), aiul lateral (C), 

 aspects, enlarged, and the sanie iiat. size 



gLtT"'^''''""^' «^^^""«^"<^^^^'- and Acanthobatis, Larr 



Taeniura, Urolophus, 

 M. and H. Upper Eocene (Monte Bolca) and 

 Recent. 



Xiphotrygon, Cope (Heliobatis, Marsh). Resembling 

 Trygon, but teeth cuspidate.' X acutid^ens, Cope, known ..IS^ji^'i^'''^^^ 

 by complete skeletons from Eocene Green River Shales hV^^^«^^\ "^^-^ ^'^^- ^locene 



f "Wt--— -• (Molasse); Baltringen. 



Fig. 84. 



yoming. 

 Oncobatis, Leidy. 



Dermal tubercles. Pliocene ; Idaho. 



