IOIO CLASS PISCES. 



Caranx (Carangopsis), Argyriosus ( Vomer), Lichia, and Trachynotus ; 

 and JEquula, from the Miocene of Sicily. 



Family Acronurid^e. — The last family of the Cottoscombri- 

 form section comprises tropical marine Fishes, popularly known as 

 Surgeons, which are readily recognised by the sharp spine border- 

 ing each side of the tail. The body is compressed, and oblong or 

 ovate, with small scales ; the front of the jaws has chisel-like or 

 pointed teeth ; and the dorsal fin is undivided, with the spinous 

 portion less than the soft. This family is represented in a fossil 

 state by species of the existing genera Naseus and Acanthurus from 

 the Middle Eocene of Monte Bolca. 



Family Trichiurid^e. — The next section of the suborder is 

 represented by the existing Scabbard-fishes and the extinct Palceo- 

 rhynchidce. These Fishes are characterised by their elongated, com- 

 pressed, or band-like bodies, furnished with long dorsal and anal 

 fins, of which the former may be divided into a number of finlets, 

 somewhat after the manner of the Ganoid genus Polypterus. All 

 these fishes are marine, and are found in tropical and subtropical 

 seas. Species of the existing genus Lepidopus (Scabbard-fish) occur 

 in the Miocene of Sicily, while Hemithyrsites and Trichiurichthys, 

 of the same deposits, are forms allied to the living Thyrsites and 

 Trichiurus, but differing by having the body scaled. Xiphopteryx 

 is another extinct genus from the European Eocene ; while Anen- 

 chylum, of the Lower Eocene of Glarus, resembles Lepidopus except 

 for the presence of some long rays in the pelvic fins, and the two 

 are probably identical. 



Family PAL/EORHYNCHiDiE. — The members of this family differ 

 from the last by the production of the jaws into a long rostrum, 

 which is either edentulous or provided with very small teeth. The 

 dorsal fin occupies the whole length of the body, and the anal is 

 also elongated and reaches nearly to the forked caudal. This 

 family is known only by Hemirhynchus from the Eocene of the Paris 

 basin, and Palceorhynchus from the Lower Eocene of Glarus. 



Family Xiphiid^e. — The Sword-fishes, which are of pelagic habits, 

 and generally attain very large dimensions, are characterised by the 

 production of the upper jaw into a long spear-like rostrum. They 

 are represented at the present day by Xiphias (fig. 944), in which 

 pelvic fins are wanting ; and Histiophorus, in which these organs are 

 long and filiform, and the dorsal fin may be of great length and 

 height. Fossil Sword-fishes from the London Clay have been 

 referred to Histiophorus {Tetrapturus), although it is not certain 

 that they may not prove generically distinct. The genus Ccelorhyn- 

 chus, which was formerly referred to this family, is noticed among 

 the Chimeroidei. 



Family BERYCiDiE. — The Berycidce are characterised by the pres- 



