148 DEEP SEA FISHES. 



Hixonus caudalis sp. n. 



Plate XXX VI. fy. 2; Plate XXXIX. fy. 2; Plate LXXIV. fi<j. 2, Lat. Syst. 



Br. r. 9 ; D. 97-103 ; A. 73-81 ; V. 2 (1) ; P. 14 + 2 ; C. 6; LI. ca. 150; 

 Ltr. 28. 



The following may be added to the generic characters as given by 

 Giinther: Branchiostegal rays nine; pyloric c?eca rudimentary; a mem- 

 branous connection between the lower two rays of the pectorals ; pseudo- 

 branchiae rudimentary ; an air bladder. 



Body elongate, compressed; body cavity little more than one third of 

 the total length. Head short, one sixth of the total, deeper than wide, 

 decidedly convex on the crown, slightly swollen at the top of the snout. 

 Snout one third longer than the eye, broad, rounded, not deep. Mouth 

 wide, anterior. Maxillary at its cud wider than the eyes, extending back- 

 ward of the orbit more tlian tlie length of tlie latter. Tongue free at 

 its edges. Teeth small, in villiforin bands on jaws, vomer, palatines, 

 and pharyngeals. Vomerine teeth in three groups, a large median at 

 the forward angle, and a small narrow group at each siile near the pala- 

 tines ; rarely the groups are imited by a slender band on one or both sides 

 of the vomer. Eye normal, small, one sixth as long as the head, one 

 half as wide as the interorbital space, three fourths of the length of the 

 snout ; orbit without the bony supraorbital covering seen in Lcucicorus. 

 A groove forward of the anterior nostril. Mucous cavities and pores 

 moderately large, arranged as in Leucicorus but less extensive. Over the 

 muciferous cavities the skin is translucent, as if the contents were lumin- 

 ous. Gill openings wide ; membranes not united, free from the isthmus. 

 Gills four, a short opening behind the fourth. Pseudobranchite small. 

 Gill rakers close together, rigid, slender, as long as the eye, upper section 

 of the first arch with three rudimentary and a couple of long ones, and 

 lower with thirteen or fourteen long ones and four or five rudiments. 

 Dorsal origin above the base of tlie pectoral. Anal origin below the 

 twenty-fifth ray of the dor.sal. Caudal extending much beyond dorsal and 

 anal, with which fins it is united near its base, narrow, acuminate, three 

 fourths as long as the head. Pectorals narrow, with two of the lower 

 rays free in the greater portion of their length, prolonged bej'ond the bal- 

 ance of the fin, reaching behind the origin of the anal fin. TIic distance 



