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PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. 51. 



the other extreme by species with a very long sturgeon-like snout. 

 Several apparently natural groups can be defined, and are here 

 regarded as subgenera. 



KEY TO THE SUBGENERA AND THE JAPANESE SPECIES OF COELOEHYNCHUS. 



A\ Subopercular margin rounded; snout moderate, not greatly produced, with 



a prominent double terminal tubercle Coelorhynchus. 



A*. Subopercular margin produced backward at the angle in a pointed flap ; 

 snout without a prominent double terminal tubercle. 

 B^. Snout usually only moderately produced ; scales with equal parallel 

 spinous ridges ; body usually with distinctive bars or spots. 



Paramacrurus. 



«\ An elongate scaleless thoracic fossa present on mid-ventral line ; body 



with a large round spot behind pectoral antl below first dorsal, and 



another below second dorsal ; orbit longer than postorbital length of 



head ; pectoral with 17 rays ; pyloric caeca 19 to 23 ; inner edge of 



shoulder girdle scaled kisliinouyci. 



a'. No naked thoracic fossa ; spot near pectoral smaller, posterior spot 

 absent ; orbit shorter than postorbital length of head ; pectoral with 

 14 to 15 rays, weaker and shorter ; pyloric caeca 25 to 31 ; inner edge 



of shoulder girdle scaled jordani. 



B^. Snout greatly produced, sturgeon-like; spinules of scales variously ar- 

 ranged, but never on equal parallel ridges; inner edge of shoulder 



girdle naked Oxymacrurus. 



6\ Spinules on scales in strongly divergent series. 



c\ Snout, with a terminal spine, less than twice as long as head in 



adults. 



(Z\ Four or five rows of scales in a series from origin of second dorsal 



to lateral line ; under side of head naked. 



e\ Three to five spinous ridges on scales ; snout longer, not shaped 



like a duck's bill ; eye 1.8 in snout ; barbel 6 in ovhit^producfiis. 



el Six to nine spinous ridges on scales ; snout shaped like a duck's 



bill ; eye 1.5 in snout ; barbel about half orbit anatiroslris. 



d^. Six or seven rows of scales in a series from origin of second dor- 

 sal to lateral line ; under side of head scaled ; barbel 3 to 4.5 



in orbit japonicus. 



&. Snout without a terminal spine, more than twice as long as eye in 



adult tokiensis. 



h'. Spinules on scales strongest on a median keel, the other spinules 

 arranged in one or two parallel rows, but not on ridges ; under side 

 of head scaled paraUeliis. 



12. COELORHYNCHUS KISpiNOUYEI Jordan and Snyder. 



Coelorhynchus kishinouyei Jordan and Snyder, Proc. U. S. Nat. SIus., 

 23, 1901, p. 376, pi. 20. 



