EASTMAN : DESCRIPTIONS OF BOLCA FISHES. 23 



120. Urosphen dubia (Blv.). Ag., IV. PL 35, Fig. 6. 



121. Vomeropsis triurus (Volta). Volta, PI. 44, Fig. 2 ; Ag., V. PI. 6. 



122. " " " Volta, PI. 35, Fig. 3 ; Ag., V. PI. 5. 



123. Xiphopterus falcatus (Volta). Volta, PI. 57. 



124. Zand us brevirostris Ag. Volta, PI. 26, Fig. 2; Ag., IV. Pi. 



38, Figs. 1, 2. 



II. SYSTEMATIC DESCRIPTIONS. 

 ELASMOBRANCHII. 



RAJIDAE. 



Platyrhina gigantea (Blv.). 



1796. Raja torpedo G. S. Volta, Ittiolit. Veronese, p. 521, Plate LXI. 



1818. Narcobatits giganteus H. D. de Blainville, Nouv. Diet. d'Hist. Nat, xxvii. 



p. 337. 

 1835. Torpedo gigantea L. Agassiz, Neues Jahrb., p. 297 (name only). 

 1843. Torpedo gigantea L. Agassiz, Poiss. Foss., iii. p. 382 ; ** iv. p. 38 (name only). 

 1860. Narcine gigantea R. Molin, Sitzungsber. Akad. Wiss. Wien, xl. p. 585. 

 1874. Torpedo gigantea A. de Zigno, Catalogo ragionato dei Pesci Fossili, p. 177. 

 1894. Platyrhina gigantea O. Jaekel, Die eocanen Selachier vom Monte Bolca, p. 



108, text-fig. 19. 



The holotype of this species is preserved in the Paris Museum of Natural 

 History, and not, as stated hy Baron de Zigno, in the second Gazola Collec- 

 tion at Verona. In its present state the disk is remarkable for its great 

 antero-posterior elongation. De Blainville was of the opinion that this was 

 not a character properly belonging to the specimen, but one due to deceptive 

 appearances, a portion of the disk having become folded upon itself. 0. Jaekel, 

 without having had access to the specimen, imagined that the disk had become 

 deformed by mechanical agencies subsequent to the death of the creature. An 

 examination of the original leads the present writer to conclude that there is 

 no evidence of a folding over of the edges of the disk, nor of distortion due to 

 pressure or other causes. Although extremely probable that the lateral mar- 

 gin of the disk escaped fossilization, it nevertheless appears certain that the 

 form was more elongated longitudinally than in the majority of rays. 



TEYGONIDAE. 



Trygon muricatus (Volta). 



1796. Raja muricata G. S. Volta, Ittiolit. Veronese, p. 37, Plate IX. Figs. 1, 2. 

 1818. Trygonobatus vulgaris 11. D. de Blainville, Nouv. Diet, d'llist. Nat. xxvii. 

 p. 336. 



