75 Zoological Society : — 



inches. 



Eye, distance from tip of snout ^ 



Eyes, distance apart ^ 



Dorsal, length of base TD 



, height 1 1 



, distance from snout o| 



Pectorals, length Is 



, width of base t 



, distance from snout 2^ 



Ventrals, length 1 



, distance from snout 4^ 



Vent, distance from snout 7| 



Anal, height of fourth and the neighbouring rays . . | 

 Caudal, two rays TO" 



' This species is dedicated to Professor Richard Owen, Superin- 

 tendent of the Natural History Departments of the British Museum, 

 whose investigations in regard to the skeleton of fishes are not the 

 least valuable part of his many contributions to zoological science. . 



Chiasmodon, gen. nov. 

 Body naked, elongate, with two perfect dorsal fins, one anal fin, 

 simple thoracic ventral fins, and distinct caudal fin. Head unarmed 

 and exappendiculate. Snout short, truncate. Cleft of the mouth 

 very long, extending much beyond the eyes. Acute teeth in two 

 series in the premaxillary and the mandible, those of the inner series 

 being moveable. Hooked teeth, and teeth that cross each other 

 from opposite sides of the mouth in the upper jaw. Teeth on the 

 palatines, but not on the vomer. Eyes lateral. Gill-openings large; 

 four pairs of gills. Seven branchiostegal rays. No pseudobranchise : 

 no anal papilla. An air-bladder. 



Chiasmodon niger, sp. n. 



1st D. 11. 2nd D. 13. A. 17. P. 12. V. 6. C. 14. M.B. 7. 



Body black, naked, moderately elongate, compressed, and slender. 

 Head unarmed, thick, subcubical, depressed, with a wide groove 

 between the eyes, and two low ridges which meet in front of them. 

 Cheeks flat ; opercle rounded behind, with a notch at the junction 

 of the subopercle and interopercle. Eyes lateral, nearly round, 

 placed about a diameter from the muzzle (in front of the middle of 

 the upper jaw) and about the same distance apart, with the orbit 

 taking part in the profile. The hinder nostril, which is the larger, 

 is placed very near the orbit. Muzzle short, truncate, subemarginate ; 

 the under jaw somewhat longer. Mouth-cleft slightly oblique, long, 

 extending much beyond the eyes ; the upper border formed entirely 

 of the slender premaxillary, the toothless maxillary being a Httle di- 

 lated at the ends. Two series of subulate teeth in' each jaw, those of 

 the inner series being longer, but fewer in number. At the fore end 

 of the upper jaw are two long immoveable hooked teeth, which are 

 inclined towards each other and nearly meet. At the base of each 

 is a minute sharp tooth. Next to the hooked pair is a pair of cur- 



