ON TWO NEW FORMS OF POLYODONT AND GONORHTNCHID FISHES. 165 



dorsal fin distiiiguislies this species from all the others of the genus. The number of spinous rays 

 is the same as in them. 



I may add that a newly acquired specimen of the Priscacara serrata displays the massive 

 superior and inferior pharyngeal bones, covered with obtuse grinding teeth. 



EXPLANATION OF PLATE. 



Figs. 1-3. CrossophoUs magnioaudatus Cope, one-half natural size, except tig. 3, whicU is iiiaguified four diameters. 



Fig. 1. One side of skull lacking the parietal bone, and other elements more or less disarranged ; from the left 

 side. Na nasal bone; J^r., frontal ; Bapo., Dermosphenotic; Pa., parietal; Pot., post-temporal; -BcZ., Epiclaviclo ; 

 Prmr., premaxillary; D., Deutaries; Hin., Hyomandibular; Op., operculum ; P., problematical element; S(., stellate 

 bones ; Dp., Deutigerous laminae. 



Fig. 2. Part of the left side of the body, lacking a piece of the caudal peduncle. Nb., neural basilars ; H b., 

 hfemal basilars; Ch., caudal haemal spines (" hypurals"). 



Fig. 3. Scales of the same magnified four diameters. 



Fig. 4. Notogonctis oscidus Cope, two-thirds natural size; A., accessory ? branchial organ; B., ? barbel axis. 



Fig. 5. Scales of do., natural size. 



Fig. 6. Priscacara hypsacanthus Cope, natural size. 



