G18 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY IV. 



rate, free from the isthmus; gills 4, a slit bc'hind the fourth. Pseudo- 

 branclme well developed, in a pouch formed by a fold of the mucous 

 membrane. Dorsal tin single, extending from the head to the tail, it3 

 rays all technically spinous, being neither articulated nor branched, 

 but all very soft, flexible, and fragile; anal tin wanting; pectorals 

 short; ventrals thoracic, the rays elongate, often less than I, 5 in num- 

 ber; caudal fin either rudimentary or else divided into two parts, the 

 upper and larger fan-shaped, directed obliquely upward from the slen- 

 der tip of the tail. Bones very soft, the muscles little coherent. Py- 

 loric creca very numerous. Vertebrae in large number. Deep-sea fishes. 

 ol'ien of large size, found in most warm seas. Their extreme fragility 

 renders them rare in collections, and the species are little known. 

 Genera 3; species about 15. They have no intimate relation with any 

 other of our families. 

 (Traohypteridce Giinther, iii, 300-311. ) 



a. Ventral fius well developed; caudal present, not in the line of the axis of the 

 body TRACIIYPTERUS, 331. 



331. TRACHYPTERUS Gouan. 



King-of-the-Herrings. 



(Gouan, Hist. Poiss. 1770, 104: typo Cepola trachyptcra Gmel.) 



This genus is characterized by the well-developed ventral fins, com- 

 posed of 4-0 branched rays each, and by the presence of a long fan- 

 siiaped caudal fin extending obliquely upward and backward from the 

 end of the long and slender tail; lower lobe of the fin little developed; 

 the anterior rays of the dorsal lin are usually elevated, and separated 

 by a notch from the rest of the fin; the tin rays and the lateral line 

 are often armed with prickles. Deep-sea tishes of large sixe. (-f>a%u;, 

 rough; -7/</i/, fin.) 



9C8. T. i&StivcSis K^N.King-of-tlus-Salmon. 



Bright silvery, with three large round black spots below the dorsal 

 fin; a fourth near the abdominal edge, a little below the lirst of the 

 back. Anterior rays of the dorsal lin elevated; the longest rays of the 

 posterior part of the dorsal nearly as deep as the body; dorsal rays 

 rough, a small spine at the base of each of them; caudal lin with the 

 civet lobe \\cll developed, ih> outer rays longer and stronger than the 

 intermediate rays: rays of the lower lobe short: skin prickly, the lat- 

 eral line armed with small bony shields, each provided with a spine. 



