THE SUCKER FAMILY. 189 



the most part with the full number in the adult. On the other 

 hand, the young differs from the latter in the greater propor- 

 tional size of the eyes ; the larger proportional size and the 

 nature of the third row of spines and of the ventral tubercles, 

 in the shape and condition of the first dorsal fin, and in the 

 arrangement of the pigment. At this as well as the previous 

 stage, minute leeches are occasionally found on the skin. 



In July, eggs were once obtained in a fully ripe condition 

 (viz. the 12th), but their deposition on the rocks would seem to 

 be rare at this period. Young post-larval forms of only 6'5 mm. 

 are still found at the surface, e.g. of St Andrews Bay and the 

 Forth, the majority, however, being between 11 and 30 mm. 

 Many of an intermediate size are obtained in rock-pools. At 

 30 mm. all the rows of spinous tubercles are extremely 

 prominent, the most conspicuous being four of the third row. 

 This and the second row extend almost to the base of the 

 caudal fin. Such a fish is much more rugose than the adult, 

 whose rows of flattened tubercles contrast with the projecting 

 ridges and their hispid tubercles in the young. The first 

 dorsal fin at this stage has a tendency to be adpressed, so that 

 its tip is guarded by the double row of spinous tubercles on the 

 dorsum. Further, the flattened abdominal surface behind the 

 ventrals shows minute soft papillae scattered over the surface, 

 the precursors of the hispid processes of the next stage. At 

 this period, therefore, the young lump-sucker is armed at most 

 points, a condition of great importance during its more or less 

 pelagic existence. 



At 38 mm. (31st July) the head and body are of a fine 

 bluish green, spotted with isolated black specks, and grained 

 all over with separate black chromatophores. The ventral 

 surface is paler. The pectoral fins have fine brownish-red lines 

 along the rays (one on each side), the lower part of the fin 

 being fawn-coloured. The eyes are remarkably tinted, for a 

 circle of pink surrounds the pupil, while a chrome-yellow ring 

 bounds the eye externally, the whole surface being minutely 

 dotted with black. Thread-worms are common in such forms. 



During August the captured specimens (in spirit) range 

 from 13'5 to 35 mm., most being above 20 mm. Large numbers 



