THE FLOUNDER FAMILY. 345 



When, however, we come to Cunningham's examples of the 

 following April, viz. 3-3 to 37 inches in the aquarium, it is 

 clear that the growth of these captive specimens falls short of 

 that in nature, unless the brill of the south differs materially in 

 this respect from the northern. On the east coast they attain 

 the length of about 5 inches in May; and in September are 

 often met with of 10 to 11 inches, which probably represents 

 the growth of a year and four or five months. Cunning- 

 ham's example of 7 '2 inches was probably a small one, or 

 pertained to a less vigorous race. The time which would 

 elapse before the brill of the east coast would reach 18 inches 

 is therefore not necessarily four years. 



MiJLLER's Topknot. (Zeugoptenis punctatus, Bl.) 



As described in the Researches', a specimen with dis- 

 tended ovaries having a few ripe eggs was found in a pool on 

 the 16th May. In the Scandinavian Fishes the spawning-season 

 is stated to be in spring and summer. Malm, again, found a 

 ripe female on the 11th June. The translucent (nearly ripe) 

 ova had a diameter of '042 in., that of the conspicuous oil- 

 globule being '008 (Plate IV, fig. 6). During the same month 

 and till July certain ova are common in the bottom tow-nets 

 in St Andrews Bay, measuring '034 by '035 in., or '996 mm. 

 (Plate IV, fig. 7). In the majority of those captured in the 

 bay the embryos were far advanced, as if they had been carried 

 by currents some distance. Yellowish pigment early appears 

 in the embryo, viz. shortly after the lenses are distinct. Before 

 hatching, the yolk and general surface are observed to be 

 reticulated and slightly papillose, or, as Mr Holt aptly terms it, 

 the whole surface exhibits a remarkable epidermal network 

 consisting of small vesicular bodies connected with each other 

 by fine lines. Active movements occurred in the advanced 

 embryo, though the impression was that the heart was some- 

 what later in commencing to pulsate than in the cod. 



After extrusion the larval fish (Plate XIV, fig. 1) measures 

 about yV*^ ^f ^^ inch, and is characterised by the presence of 

 1 M'lntosh and Prince, Trans. R. S. E., p. 852. 



