THE OOD FAMILY. 293 



marks, viz., 37'5 mm., with silvery sides, minutely speckled with 

 black; 40 mm., also silvery and with similar black specks; 43 mm. 

 without silvery lustre, and with bold black specks all over the 

 body and tins, while the filament of the first dorsal is long ; 

 52 mm., without silvery lustre, and with black grains all over. 

 All these are the young of the preceding year. It is possible 

 also that one of 70 mm., with black specks over the head 

 and body, as well as faintly on the fins, may be an early one 

 of the same year as the foregoing. The two first rays of the 

 ventrals are conspicuously tactile, the second being the longer. 

 Six other rays are visible. In April, young rocklings If inch 

 long are occasionally met with at the surface. One of 80 mm. 

 in July (Guernsey) appears to be a continuation of the series. 

 In August at St Andrews, the smaller specimens range from 

 If to 4f inches ; while at Lochmaddy the higher limit is 5 inches 

 during the same month. The larger are probably in their 

 second year. The same may be said of those at 103 mm. in 

 February, and of 110 and 133 mm. in November. Those of 

 65 inches are somewhat older. 



Mr Cunningham found that specimens 1 inch long on 

 21st May were 3J, inches in August in the tanks of the 

 Laboratory at Plymouth ; while in May of the following year 

 one had grown to a length of fully 5 inches. He does not, 

 however, make clear the age of the examples measuring one 

 inch. 



Day observes that, at an early stage, the five-bearded 

 rockling may be distinguished from the three-bearded by the 

 presence in the former of dull yellowish rays in the dark 

 ventral fins. When nearly an inch long by the five barbels, 

 by the brownish hue of the back and trunk (not always present). 

 The eyes are smaller, the space between them broader, and the 

 barbels are longer ; the first dorsal fin is also longer from 

 before backwards. 



One reference is here necessary. Cornish (1879) states, in 

 speaking of the five-bearded rockling, " The nest wherein the 

 spawn is deposited is invariably formed of the common coral- 

 line, Corallina ojficinalis, thrust into some cavity or crevice of 

 a rock close to low-water mark.' 



