120 NOTES ON TFIE REPRODUCTION OF TELEOSTEA.N FISHES 



seems to throw an important light on the phylogeny of the whole 

 Scombroid tribe. It appears almost certain that Caranx has been 

 evolved from a somewhat elevated laterally compressed ancestor, 

 bearing in this respect a resemblance to the Capros of the present day. 

 An elevated compressed form may therefore have been a primitive 

 feature in the evolution of a part of the tribe, intensified in the 

 evolution of various genera, such as Zeus and Platax, reduced in others, 

 as certainly in Caranx, and perhaps in Lichia. Scomber has lost in its 

 ontogeny all trace of an elevated ancestry, if it ever possessed one. The 

 importance of a primitive elevated and compressed form may extend 

 far beyond the limits of those fish which are usually associated in the 

 broadest sense as Scombroids. As a matter of pure conjecture it may 

 even be suspected to throw light on the systematic position of the 

 Pleuronectida?. I have already suggested {Proc. Zool. Soc, 1894, 

 p. 438) that these fish are derived from vertically swimming but 

 elevated and laterally compressed ancestors, and the absence of stout 

 spines in the fin-rays, considering the requirements of the habit 

 evolution, requires no explanation at all. 



Capros aper. Linn. Cuckoo, Boarfish. 



Cunningham, J. T., Journ. M. B. Assoc, N.S., i., 1889, p. 10. Early stages of 



egg derived from parent. 

 Holt, E. W. L., ibid., v., 1897, p. 41. JEV/j and larvcc derived from imrent ; 



toiv-nct egg and larva ; late larvcc referred to C. ajicr. 

 Holt, E. W. L., Ann. Mus. Mars., v., 1898, Fasc. II. As above, illustrated by 



numerous figures. 



With regard to the ova, I have little to add to the observations 

 published in the last number of the journal. It will be seen from 

 our records that the species must have been spawning in the neigh- 

 bourhood of Plymouth from the beginning of June to the end of 

 August. Trawlers regard it as a vagabond, here one day and gone 

 the next, but never moving very far as long as it favours the coastal 

 waters with its unwelcome presence. It was noted on the 3rd August 

 that no cuckoos were caught in the trawl, though their ova, in an 

 early stage of development, were fairly numerous on the surface above 

 the ground trawled. So closely do these fish seem to congregate that 

 a large shoal may have been quite near us at the time. 



It appears worth while to recapitulate from our records the sizes 

 of the eggs measured on different dates, in order to set forth what 

 evidence we have of the diminution in size towards the end of the 

 season. The notes of interrogation signify a doubt as to the correct 

 determination of the species. 



