EASTMAN: FISHES FROM UPPER EOCENE OF MONTE BOLCA. 343 



Genus Pterygocephalus Agassiz. 



Head short and orbit very large; mouth small, with conical teeth. Vertebrae 



about ten in the abdominal, fourteen in the caudal region. Dorsal fin very high, 



the foremost large spine displaced forwards above the head, but the fin otherwise 



continuous, each scale with a longitudinal keel, and the keels forming regular lines 



along the trunk. 



16. Pterygocephalus paradoxus Agassiz. 



(PL XLV, Fig 5). 



1796. Labrus malapterus G. S. Volta, Ittiolit. Veronese, p. 228, PI. LV, fig. 3 



(errore) . 

 1818. Labrus malapterus H. D. de Blainville, Nouv. Diet. d'Hist. Nat., Vol. 



XXVII, p. 351. 

 1835. Pterygocephalus paradoxus L. Agassiz, Neues Jahrb., p. 295 (name only). 

 1839. Pterygocephalus paradoxus L. Agassiz, Poiss. Foss., Vol. IV, p. 191, PI. 



XXXII, figs. 5, 6. 

 1853. Cristiceps paradoxus J. Miiller, Neues Jahrb., p. 123. 

 1876. Cristiceps paradoxus F. Bassani, Atti Soc. Veneto-Trent. Sci. Nat., Vol. Ill, 



p. 178. 

 1901. Pterygocephalus paradoxus A. S. Woodward, Cat. Foss. Fishes, Pt. IV, p. 595. 

 1905. Pterygocephalus paradoxus C. R. Eastman, Mem. Soc. Geol. France, No. 34, 



p. 29. 

 1911. Pterygocephalus paradoxus C. R. Eastman, Mem. Car. Mus., Vol. IV, No. 7, 



p. 388, PL XCVI, fig. 5. 

 Type. — Imperfect fish; Paris Museum of Natural History. 

 This, the type-species, includes small-sized fishes allied to the existing Cristiceps, 

 the total length not much exceeding 5 cm. Length of head with opercular apparatus 

 equalling maximum depth of trunk and somewhat less than one-third of the total 

 length of the fish to the base of the caudal fin. Separate dorsal fin-spine about 

 twice as long as the next, the length of which slightly exceeds depth of trunk 

 at its point of insertion ; continuous dorsal fin with nine spines and nine articulated 

 rays; anal fin with three spines and seven articulated rays. 



Two examples of this rare and interesting form are preserved in the Bayet 

 Collection of the Carnegie Museum; one, cataloged as No. 4215, which has already 

 been figured, and another which is larger and more perfect, cataloged under the 

 numbers 5309-|-5309o. In this latter, which is in counterpart, all of the fins, the 

 details of the squamation, and arrangement of cranial plates are very favorably 

 displayed. 



