272 MARKETABLE BRITISH MARINE FISHES 



fathoms line, and only makes temporary migrations into shallower 

 water. In the works of Day and Couch are quoted stories of its 

 coming ashore in the Orkneys spontaneously, with its. tail erected 

 above the water to act as a sail ; and the name sail-fluke is said 

 to be derived from this peculiar habit. Whether there is any 

 important fact concerning the habits of the fish at the base 

 of these stories is uncertain, but at an}'- rate no one would 

 take them seriously without the evidence of some competent 

 observer. 



Food. — According to the observations made in the Irish 

 Survey, the principal food, as in the case of the turbot and brill, is 

 fish, namely, sprats, sand-eels, whiting, gobies, &c. Crustaceans, 

 common shrimp and others, and squid, were found in one or two 

 specimens. 



Breeding. — Dr. Fulton found that the females were both 

 larger and more numerous than the males, but as he only 

 examined twenty-one specimens, too much importance must not 

 be given to his figures. The proportions were in number 

 133 to 100, in length 131 to 100. On the west of Ireland the 

 numbers found were : males 43, females 160, or 372 females to' 

 100 males. 



On the west of Ireland these fishes were spawning in March, 

 April, and May. Spawning fish were only taken at 53, 154, and 

 200 fathoms, a fact which confirms the suggestion that the species 

 belongs properly to the deep water. Numbers of specimens 

 were taken in shallower water, but though some were mature 

 none were ripe. The number of ova in a female 18 inches long, 

 was found on calculation to be 440,000. 



The eggs are like those of the turbot and brill, having a 

 simple yolk with a single oil-globule. In size they most resemble 

 those of the turbot, their breadth being 1-13 mm. (tMo- inch). 

 They have been examined both in the Irish Surve}' and at St. 

 Andrews. Hatching took place on the sixth and seventh days 

 after fertilisation. The larva was distinguished from those of 

 most other flat-fishes by the almost entire absence of coloured 

 pigment, the black specks being scattered equally over the 

 head, body, and fin-membrane, but not on the )'olk sac. The 

 oil-globule is placed at the hinder end of the yolk, and the end 

 of the intestine is slightly separated from the yolk sac. When 

 the larvae were four or five da}'s old, the mouth became open 



