454 ^"EW BATHYBIAL FISHES— GOOBE AND BEAN. vol.xvii. 



EoNDELETiiD^. iiew family. 



Body more or less compressed, scaleless. Head naked. No barbels. 

 Mouth large. Margin of the upper jaw formed by the premaxillaries 

 only. Teeth coarsely granular. Opercular apparatus complete; its 

 bones very thin, membrane-like. No adipose fin. Dorsal fin far back; 

 short and low; inserted opposite the anal. Pectorals short, placed 

 rather low. Ventrals present, abdominal. Gill opening very wide; 

 membranes deeply cleft, free from tho»isthmus. Pseudobranchite absent. 



R O N D E L E T I A, new genus. 



Body oblong, compressed, scaleless. Moutli large ; lower jaw slightly 

 projecting. Teeth in bands, coarsely granular in the jaws; vomer and 

 palatines toothless; a row of large mucous pores on the lower surface 

 of the mandible and extending upward on the preoperculum. Posterior 

 nostril with a slender filament anteriorly. Eyes moderate; near the 

 dorsal profile. Snout rather long, obtuse, Supraoccipital bones Avith 

 a pair of strong spines projecting horizontally forward over the orbit. 

 Gill-membranes entirely separate; gill-rakers numerous, rather long and 

 slender. Gills 4; a narrow slit behind the fourth. Branchiostegals 7, 

 Opercular bones thin, membranous. Dorsal short, rather low, opposite 

 and similar to the anal. Pectorals and ventrals small. Caudal small, 

 l)robably forked. No vestiges of a lateral line. 



This genus is dedicated to Rondelet, the French ichthyologist of the 

 seventeenth century. 



RONDELETIA BICOLOR, r/ew species. 

 Plate XVII, Fig. 1. 



Tlie height of the body is a little less than one third of the total 

 length; length of the head nearly one-half. Diameter of the eye con- 

 tained six times in the length of the head, and twice in the length of 

 the snout. The maxillary reaches to below the hind margin of the eye, 

 and the intermaxillary about as far. Origin of the dorsal fin nearly 

 opposite the vent. The anal origin immediately behind the vent, the 

 terminations of the two opposite. The fins are low, the rays pointing 

 horizontally backward ; the longest ray in the dorsal fin about one- fifth 

 of tlie length of the head, and the longest in the anal, one fourth. The 

 pectoral fin inserted below the middle of the body, and under the end 

 of the opercular flaj); its length nearly one-fourth that of the head. 

 Ventrals inserted behind the middle of the total length, and still farther 

 behind the tips of the extended pectorals ; their length about two-ninths 

 that of the head, and when extended reaching beyond the vent. 



Color, purplish-black, with cherry-colored margins to the fins; whit- 

 ish in spirits. 



Eadial formula: B. 7; D. 14; A. 14; P. 9; V. 5. 



A single specimen (No. 38202, U.S.N.M.), 4:| inches in length, was 

 taken by the Fish Commission steamer A //>n/ro,s.s at station 2724, Lat. 

 300 47' is^., Lon. 73° 25' W., at a depth of 1,041 fathoms. 



