68 DEEP-SEA FISHES OF THE ATLANTIC BASIN 



RONDELETIA, Goode and Bean, n. g. 



Body oblong, compressed, scaleless. Mouth 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 inaudible, 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 with a pair of 

 strong spines projecting horizontally forward over the orbit. Gill membranes entirely sep- 

 arate; 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, probably 

 forked. No vestiges of a lateral line. 



Dedicated to Rondelet, the great French ichthyologist of the seventeentn century. 



RONDELETIA BICOLOR, Goode and Beau, n. 8. (Figure 77.) 



The 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 contained (i times in the length of the head, and 

 twice in the length of the snout. The maxillar i caches to below the hind margin of the 

 eye, and the intermaxillary about as far. Origin of the dorsal tin 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 the length of the head, and the longest in the anal one-fourth. The pec- 

 toral fin inserted below the middle of the body, and under the end of the opercular flap; 

 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; whitish in spirits. 



Radial formula: B. VII; D.14; A. II; P.9; V. 5. 



A single specimen (No. 38202, U. S. N. M.), 4} inches in length, was taken by the Fish 

 Commission steamer Albatross at station 2724, lat. 36 47' N., Ion. 73° 25' W., at a depth 

 of 1,641 fathoms. 



Family CETOMIMID^E, Goode and Bean. 



Iniomi with body somewhat compressed, scaleless. Head naked. Lateral line con- 

 spicuous. No barbels. Mouth exceedingly large: the margin of the upper jaw formed by 

 the premaxillaries only; the lower jaw strongly curved, and slightly projecting beyond the 

 upper. Teeth in jaws in bands, granular. The vomer, the palatines, the pterygoids, and 

 also the first gill arch and the lingual bones (which are greatly enlarged), as well as the upper 

 pharyngeals, are covered with teeth of a similar character. Opercular apparatus incom- 

 plete; its bones very thin, membrane like. No adipose fin. Dorsal fin far back, short, high, 

 inserted opposite the anal, which it resembles. Pectorals short, placed rather low. Ven- 

 trals absent. Gill opening immense, the membranes deeply cleft, free from the isthmus. 

 Gills 3. Pseudobranchiai absent. 



CETOMIMUS, Goode and Bean, n. g. 



Body oblong, compressed, scaleless: similar in its vertical outline and proportions to 

 that of the right whales (Balcenidce), a resemblance which is greatly enhanced by the shape 

 of the enormous mouth; and in the lower jaw strongly curved, projecting slightly beyond 

 the snout. Teeth in granular bands, covering all the bones of the mouth, tongue, and throat. 

 Mucous pores sometimes present on the back. Nostrils far forward; open slits without 

 flap. Eyes very small, and placed far below the dorsal profile. Gill membranes deeply cleft, 

 not attached to the isthmus. Gill rakers absent; replaced by granular tooth -like surface 

 upon the arch. Gills 3; no slit behind the third. Branchiostegals 9. Opercular apparatus 

 incomplete, bones thin and membranous. Dorsal short, high, inserted very far back, 



