No. 3 (1922) GREY MULLETS OF TUTICORIN 79 



the difference is never greater than one. The count is taken from 

 between the two dorsal fins on the dorsal side to between the 

 pelvic fins and the anus on the ventral side. 



3. Frontal scales. — Descriptions frequently include the number 

 of scales present between the first dorsal fin and the end of the snout, 

 but I have found that in the vast majority of mullets an accurate 

 count of these scales was impossible, owing to their irregular dis- 

 posal and, still more, to the damage, nearly always found, to the 

 scales on the top of the head. I have therefore been obliged to 

 ignore this character in these descriptions. 



4. Elongated scales. — In all the specimens of mullets which I have 

 examined, I have found an elongated scale at the base of the first 

 dorsal fin and the pelvic fins ; usually, the scale is distinctly elong- 

 ated, but sometimes somewhat reduced. Some specimens have two 

 elongated scales at the base of the dorsal fin on each side, and these 

 two overlap ; they are sometimes the beginning of the additional 

 short longitudinal series between the first and second dorsal fins. 



An elongated scale is also found in certain species in the axil of 

 the pectoral fin ; the raising of this fin reveals this scale, which is 

 usually pointed. In other species, there is no trace of a scale which 

 can be designated axillary ; however, a short, blunt, soft, scale may 

 be present in this position, but such a scale has not been regarded 

 as an axillary scale in these descriptions, the name being reserved 

 for the elongated form. Where it is absent, it is quite possible that 

 the elongate axillary scale may have become detached ; I have 

 found it quite loose and easily detachable, and in some cases it has 

 been present on one side, but not on the other; hence, in speci- 

 mens which tally completely with the type except for the posses- 

 sion of the elongated axillary scale, it is well to consider the 

 possibility of its having become detached. 



THE POSITION OF FINS. 

 I. The dorsal fins. — One of the most reliable points for identifi- 

 cation purposes is the position of the dorsal fins in relation to the 

 scales of the lateral line ; a fair decree of constancy in this charac- 

 ter is maintained for each species, particularly in the case of the 

 first dorsal fin ; in fact, a recorded variation of more than one is 

 usually attributable to an error due to difficulty in counting. With 

 the second dorsal fin, a variation of two may be met with ; for 

 example, if for a particular species, the first dorsal normally begins 

 above the Ilth scale of the lateral line, specimens may be 

 2 



