1888.] PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 605 



Dr. Giinther formulated no such generalization. What he really did 

 was to show that tbe species of Labrids (and those ouly) living in the 

 temperate seas had more numerous vertebra? than those occurring in 

 the tropical waters. His words are these, referring only to the LabridcB : 



In those genera which are composed entirely or for the greater part of tropical 

 species, the vertebral column is composed of twenty-four, or nearly twenty-four, ver- 

 tebra, whilst those which are chiefly coufined to the temperate seas of the northern 

 and southern hemisphere have that number increased in the abdominal and caudal 

 portions.* 



There is no evidence that Dr. Giinther had appreciated any further 

 correlation in fishes generally. The context shows plainly that he did 

 not mean to extend his generalization beyond the Labrids. 



The first indication that there was a correlation among fishes gen- 

 erally between an increase in the number of vertebrae and increase of 

 latitude or decrease of temperature, was published by myself in 1863,t 

 the year after the publication of Dr. Giinther's volume, in the following 

 terms : 



Dr, Giinther has eunnciated for the, first time a most important generalization for 

 the Labroids which may also be extended to other families.]; * * * * This gen- 

 eralization is applicable to the representatives of Acanthopterygian families gener- 

 ally, and can be considered in connection with the predominance of true Malacoptery- 

 giau§ fishes in northern waters, fishes in which the increase in the number of ver- 

 tebrae is a normal feature. 



Later ,|| I also remarked that " the increase in the number of vertebras 

 in the species of Sebastes, a genus peculiar to the northern seas, affords 

 an excellent example of the truth of the generalization claiming an in- 

 creased number of vertebrae for the cold-water representatives of Acan- 

 thopterygians." The case of the Sebastines became still more striking 

 when Messrs. Jordan and Gilbert discovered that the number of the 

 vertebras in the species of Sebastichthys and Sebastodes, genera inter- 

 mediate between the northern Sebastes and the tropical and subtropical 

 representatives of the family of Scorpamids, was also intermediate. 



But while claiming the generalization that there is a correlation be- 

 tween the increase of vertebras and increase of latitude among fishes 

 generally, I would not assign to it an undue value or claim for it the 

 dignity of a law. It is simply the expression of a fact which has no 

 cause for its being now known, if it shall ever be known. It may also 

 be added that the generalization is true only in a general sense. 



* Catalogue of the Fishes in the British Museum, v. 4, p. 65, note on Labridte. 



t Notes on the Labroids of the Western Coast of North America, by Theodore Gill. 

 <Proc. Acad. Nat. Sci. Phil., 1863, p. 221. 



|The part omitted is the paragraph already quoted from Dr. Giinther's work. 



§ It will be evident that the term " Malacopterygian" was used in the Cuvierian 

 sense and applied especially to the Pleuronectids and Gadids as well as the restricted 

 Malacopterygians of later writers. 



HProc. Acad. Nat. Sci. Phila., 1864, p. 147. 



