42 Shufeldt — Robert Collett on Pterycombus brama Fries. 



remarkable form by Professor Lutken. It occurs in that volume of 

 " Spolia Atlantica" in which he describes the various stages of develop- 

 ment in the young of the pelagic Acanthopterygians (and of Scombresox), 

 and he there presents (7) illustrations and descriptions of a very young 

 fish taken from the intestine of an "Albacore" (Thunnus alalonga) in 

 Lat. 8° N. Long. 24° W., that is to say, a little to the southward of the 

 Cape Verde Islands. The length of this specimen was twenty-two milli- 

 meters. 



This young fish, although found in the tropical zone of the Atlantic 

 Ocean, is nevertheless considered by this author as belonging to Ptery- 

 combus, and possibly a specimen of Pterycombus brama, a species hitherto 

 considered as occurring only in the subarctic seas. Should this conjecture 

 be confirmed through the discovery later of adult specimens, it would go 

 to prove that the species is not confined to the seas of the North, but is 

 rather to be considered as having a wider range, extending even to the 

 deep seas of the middle and north Atlantic; and that occasionally it may 

 have been carried out of its habitat through the agency of the warmer 

 ocean currents, and thus have strayed to the northern coasts. 



In the paper just cited, Professor Lutken places Pterycombus in the 

 family Bramidse. Gill, in 1872, in his "Arrangement of the Families of 

 Fishes" (Smiths. Miscell. Collect. No. 247, Washington, Nov., 1872) 

 had already divided the Coryphsenidernes into several families of which 

 the Bramidse and the Pteraclididse, which contain respectively Brama 

 and Pteraclis, were two; in 1892, Jordan and Gilbert, in their " Synopsis 

 of the Fishes of North America" (Bull. U. S. Nat. Mas., No. 16, Wash- 

 ington, May, 1882) places both of these genera in the family Bramidse, 

 and which, according to Professor Lutken, includes the genus Ptery- 

 combus. 



In his " Scandinavian Fauna: Fishes" (9), Professor Lilljeborg in 1891 

 next gives us a new and revised description of this form, in which its 

 specific characters are most clearly determined. Here the species is still 

 retained in the family Coryphsenidse. 



In 1892 Professor Smitt, in the revised edition of Wright, Ekstrom and 

 SundevalPs "Scandinavian Fishes" (10) invites attention to the close 

 similarity in the matter of the Morphology of the scales in Pterycombus 

 (and Brama) as compared with the Pycnodonts from the Liassic,* the 

 latter being a group distinguished by its peculiar pleurolepine scales 

 arranged in rib-like rows, the nature and structure of which has not, as 

 yet, been fully determined. 



In his account of this species, Smitt, who at the time had before him 

 only two dried and imperfect specimens, gives us an exhaustive descrip- 

 tion of the scales and the fins.f In addition to the illustration showing 



* Woodward, Cat. Foss. Fishes, Brit. Mus. Pt. Ill, p. 189, Lond., 1895. 



tin his differential diagnosis of the two genera Pterycombus and Brama, he men- 

 tions (as did Lilljeborg in his above cited paper of 1891) the fact, and refers to it as an 

 important character, that the skin on the unpaired fins is scaleless in Pterycombus, but 

 is scaled in Brama. This is not invariably the case in well-preserved specimens of 

 Pterycombus where we meet with a row of minute scales on the skin between the spines 

 of the anterior portion of the fins, and in the case of the caudal fin, along the upper 

 and lower rays. 



