0, PACHYUKUS. 283 



two dorsals. The second spine of the dorsal fin is shorter than the 

 two following, Avhich arc the longest, and three-fifths of the height of 

 the body. The following spines decrease in length to the tenth, which 

 is one-third of the longest. All the spines are very slender and flexible. 

 The soft dorsal gradually becomes lower behind, and has a straight 

 upper margin ; the length of its base is 3| in the total length ; it 

 is much lower than the spinous portion, and covered with scales for 

 three-quarters of its height. The distance between the dorsal and 

 caudal fins about equals the height of the tail below the end of the 

 former. The middle rays of the caudalis are prolonged, the upper lobe 

 being more angular, the lower more rounded ; all the fin is thickly 

 enveloped by scales. The base of the anal fin is situated vertically 

 below the third quarter of the soft dorsal ; the first spine is very 

 small ; the second of moderate strength, shorter than the first ray, 

 and one-tliii'd of the length of the head. The soft portion is lower 

 than the second dorsal, and \vithout any scales. The pectoral is 

 pointed, and its length one-sixth of the total ; the ventral is in- 

 serted behind the pectoral, and rather shorter, its length being 6| in 

 the total. The spine is moderate, compressed, flexible at the tip, and 

 two-thirds of the length of the first ray. The first ray is produced 

 into a short filament, but is distant from the vent. 



The scales are rather small, somewhat higher than long, and very 

 finely cihated ; one of the largest covers one-fifth of the eye. The 

 lateral line is slightly curved, and not continued on the caudal fin. 



The teeth are minute and scarcely perceptible in the upper jaw ; 

 in the lower they form a fine \'illiform band. 



inches, lines. 



Total length 9 4 



Height of the body 2 1 



Length of the head 2 5 



Longitudinal diameter of the eye 7^ 



Vertical diameter of the eye 5| 



Length of the third dorsal spine 1 3| 



Length of the second dorsal ray 1 



of the caudal fin 1 8 



of the second anal spine 9 



of the first anal ray 11 



of the pectoral 1 7 



of the ventral 1 5 



of the base of the spinous dorsal . . 1 6 



of the base of the soft dorsal .... 2 9 



of a large scale 2 



Height of a large scale <» 2^ 



