jordan-snyder] collection of fishes from japan 233 



width of free edge of fin equal to height of fin. Insertion of anal 

 slightly posterior to that of second dorsal, the length of its base 

 equal to that of upper jaw, measured from angle of mouth to 

 anterior edge ; height of fin contained 2^$ times in length of base ; 

 width of free edge a little less than height of fin. 



Distance between anal and origin of caudal ijf/2 times diameter 

 of eye ; caudal with a deep notch on postero-ventral side, the dis- 

 tance between origin of fin and notch 4^ times depth of caudal 

 peduncle at origin of fin. 



Anterior edge of base of pectoral below third gill opening ; width 

 of base of fin 3^ in head ; length 2. Origin of ventral on a vertical 

 a little anterior to end of base of dorsal ; length of anterior edge of 

 fin 2]/^ in head ; free edge 4. 



Color on both dorsal and ventral surfaces dark gray ; fins includ- 

 ing the first dorsal edged with blackish. 



This species seems to differ considerably from the Atlantic form 

 P. microdon, Capello. The writers have not seen the original de- 

 scription and figure of P. microdon, but rely on that of Giinther, 

 after Capello, and also on an account of an example from Long 

 Island, published by Bean.^ Comparisons of measurements given 

 by Bean and similar ones from the species in hand follow : 



P. microdon. P. acrales. 



Snout about twice as long as About ijA times, 

 distance from its tip to mouth. 



Tip of snout to last gill open- 45^ times, 

 ing 5 times in total length. 



Height of head at angle of 14^ times, 

 mouth 1 1 times in total length. 



The distance of mouth from Distance from tip of snout to 



snout measured on axis of fish anterior edge of mouth i}i in 



equals one-third width of mouth, width of mouth ; from tip of 



The distance from snout to angle snout to angle of mouth ij^ in 



of mouth obliquely taken equals distance between tip of snout and 



one-fourth the distance from last gill opening; from angle of 



snout to last gill opening. mouth to its anterior edge meas- 

 ured on upper jaw, 3 times. 



Distance between nostrils 2^ times, 

 equals 4 times the distance be- 

 tween eye and spiracle. 



^ Bean, Tarleton H. The first occurrence of Psetidoiriacis microdon, Ca- 

 pello, on the coast of the United States. Proc. U. S. Nat. Mus., vol. vi, 

 1883, p. 147. 



