Salmopercas and Other Transitional Groups 245 



The opah is a rare fish, swimming slowly near the surface and 

 ranging very widely in all the warm seas. It was first noticed 

 in Norway by Gunner, the good bishop of Throndhjem, about 

 1780. It was soon after recorded from Elsinore, Torbay, and 

 Madeira, and is occasionally taken in various places in Europe. 

 It is also recorded from Newfoundland, Sable Island, Cuba, 

 Monterey, San Pedro Point (near San Francisco), Santa Cata- 

 lina, Honolulu, and Japan. 



The specimen studied by the writer came ashore at Mon- 

 terey in an injured condition, having been worsted in a struggle 

 with some better-armed fish. 



Allied to Lampris is the imposing extinct species known as 

 Semiophorus velifer from the Eocene of Monte Bolca near Ve- 

 rona, the type of the extinct family of Semiophoridce. This is 

 a deep compressed fish, with very high spinous dorsal and 

 very long, many-rayed ventrals. Other related species are 

 known also from the Eocene, There is no evidence of any 

 close relation between these fishes with Caranx or Platax, with 

 which Woodward associates Semiophorus. 



The SemiophoridcB differ from the Lamprididaz chiefly in the 

 development of the spinous dorsal fin, which is composed of 

 many slender rays. 



Suborder Zeoidea. Not far from the Selenichthyes and 

 the Berycoidei we may place the singular group of John 

 Dories, or zeoid fishes. These have the ventral fins thoracic 

 and many-rayed, the dorsal fin provided with spines, and the 

 post -temporal, as in the 'Chcutodontidce, fused with the skull. 

 Dr. Boulenger calls attention to the close relation of these 

 fishes to the flounders, and suggests the possible derivation of 

 both from a synthetic type, the Amphistiida, found in the 

 European Eocene. The Amphistiidcz, Zeida, and flounders 

 are united by him to form the group or suborder Zeorhombi, 

 characterized by the thoracic ventrals, which have the rays 

 not I, 5 in number, by the progressive degeneration of the fin- 

 spines and the progressive twisting of the cranium, bringing 

 the two eyes to the same side of the head. It is not certain 

 that the flounders are really derived from Zeus-like fishes, but 

 no other guess as to their origin has more elements of proba- 

 bility. 



