294 THE COD FAMILY. 



This statement is directly at variance with the facts above 

 stated concerning the pelagic habitat of the rockling's eggs, 

 and as these were actually spawned by the captured females 

 in St Andrews Laboratory we can only conclude that the eggs 

 and nest described above were those of another shore-frequent- 

 ing fish. 



THE FOUR-BEARDED ROCKLING. (Onos cimbrius, L.) 



The eggs of this species have doubtless been frequently 

 captured, but their exact identity still remains to be fixed. 

 Whether, in view of Dr Raffaele's diagnosis of the egg of the 

 three-bearded rockling as having a diameter of 74 mm., the 

 larger egg to be dealt with subsequently belongs to this form or 

 not, future observations alone can show. At any rate three 

 different forms of rocklings' eggs are met with in the tow-nets. 

 The species is common in the deeper water of the Forth, on 

 various fishing-banks and off the Isle of May, and its younger 

 stages are probably confounded with those of the other two 

 species. It is only when the characters are beyond doubt that 

 it is at present separated from its allies. 



When about 27 mm. long (October 30th), or slightly more 

 than an inch, this species is readily distinguished from the five- 

 bearded form of the same length by the more slender caudal 

 region of the body, and the diminished depth just in front of 

 the tail, by the smaller extent of the first dorsal, and its longer 

 filament, by the larger barbel on the chin, and by the more 

 distinctly mottled condition of the pigment along the dorsum. 

 The presence of the characteristic barbels makes diagnosis 

 certain, the median on the upper lip being the last to appear. 



One of 38 mm. (November 2nd) showed a smaller median 

 barbel on the lip than the preceding. 



In April of the second year they probably attain a length 

 of 40 mm. and upwards. One of the latter size was procured 

 at the surface on Smith Bank, off Caithness, on the 9th of this 

 month. 



