204 ME. C. TATE KEGAN ON THE 



yS. 28-30 scutes in a longitudinal series ; caudal peduncle 3f-5 times 

 as long as deep. 



Scutes mostly carinate ; length of base of dorsal greater than 



its distance from adipose fiu 2. P. commersonii C. & V. 



Only the anterior scutes carinate ; length of base of dorsal 

 equal to (young) or less than (adult) its distance from 



adipose fin 3. P. punctatus C. & V. 



7. 32-34 scutes in a longitudinal series. 



Caudal peduncle 7 times as long as deep 4. P. spinosissimus Stdr. 



Caudal peduncle 11 times as long as deep 5. P.festce Blgr. 



2. Supraoccipital bordered posteriorly by a median scute and by one or more on each 



side; first dorsal ray about as long as the head. 



a. Caudal peduncle normally formed, the scutes of the fourth series not strongly angulated. 



26-28 scutes in a longitudinal series, the upper and anterior 



carinate 6. P. verves C. & V. 



30 scutes in a longitudinal series, all carinate 7. P. carinatus Stdr. 



27-28 scutes in a longitudinal series, none of them carinate . 8. P. vaillanti Stdr. 

 /3. Caudal peduncle broad and flat below, the scutes of the fourth series strongly angulated. 



28-30 scutes in a longitudinal series 9. P. emarg'matus C. & V. 



3. Supraoccipital entirely bordered posteriorly by a single 



scute ; first dorsal ray as long as the distance from the 

 tip of snout to its base ; scutes not carinate, 27-28 in a 

 longitudinal series 10. P. alatus Casteln. 



E. Length of mandibular ramus H-2j times in the interorbital width. 



1. Some of the scutes carinate, the keels sometimes very weak. 

 a. Depth of body 6-t— 8 times in the total length. 



Depth of head 2j times in its length ; 30 scutes in a longitudinal 



series 11. P. cordovce Gthr. 



Depth of head ] § times in its length ; 28 scutes in a longitudinal 



series 12. P. borellii Blgr. 



/3. Depth of body 4-5 times in the total length ; 25-27 

 scutes in a longitudinal series ; diameter of eye 5^-7 

 times in the length of head. 

 First dorsal ray not reaching adipose fin when laid back ; barbel as 



long as \ the diameter of eye, or less 13. P. latirostris Hg*i. 



First dorsal ray reaching adipose fin when laid back ; barbel as long 



as diameter of eye 14. P. ternetzi Blgr. 



y. Depth of body 4-5 times in the total length ; 

 27-28 scutes in a longitudinal series ; diameter of eye 

 10 times in the length of head (in a specimen of 

 205 mm.) 17. P. robini C. & V. 



2. None of the scutes carinate. 



a. Supraorbital edges strongly raised ; eye large. . . .15. P. macrops Eigmn. 



