298 DEEP SEA FISHES. 



dorsal base backward of the latter, longest ray twice the orbital length. 

 Ventrals small, shorter than the snout, united by membrane. Pectorals 

 small, narrow, acuminate, equal the rostrorbital length of the head, distant 

 from the dorsal little more than twice the rostral length. In the tail the 

 filamentary portion is not far from one seventh of the total length. 



Scales medium, thin, each concentrically striate in its backward half and 

 in its anterior section marked with longitudinal grooves diverging forward ; 

 twelve scales above the lateral line and five below it ; those of the line wider 

 but of the same length as the adjacent scales. 



Branchiostegal membranes, throat, intestines, and linings of body cavity 

 black ; sides of head blackish, except mucous canals and luminous organs, 

 which are light colored ; muscular portions light reddish brown, probably 

 more brilliant in life. Air bladder nacreous. Described from an adult 

 female. 



Halosaurus radiatus sp. n. 



Plate LX. figs. 2, 2a; Plate LXXXIV. fijs. 3-6. 



Br. r. 21-23; D. 11 ; V. 9 ; P. 14. 



Body elongate, compressed, rather stout and broad backed near the head, 

 tapering to slender in the caudal region, depth in front of the dorsal fin one 

 eleventh of the total length. Head high at the nape, descending and acumi- 

 nate forward. Snout moderately produced, preoral about half of the prena- 

 rial length, preorbital length twice the length of the orbit, slightly broadened 

 or shovel shaped at the end. Mouth small, inferior, half as long as wide, 

 length near three fifths of that of the eye. Maxillary with a sharp spine, 

 reaching little behind a vertical from the front of the orbit. Teeth very 

 small, subconical, hooked, with a slight swelling in the bend near the point, 

 strong toward the base, in villiform bands on jaws, palatines, and pterygoids. 

 Eye large, hardly more than one sixth of the head, one half as long as the 

 snout, equal to the width of the interorbital space. Nostrils close to the 

 eye, close together; posterior larger, crescent shaped; anterior with a 

 hood-like valve opening forward. Opercles flexible, thin. Branchiostegal 

 rays numerous, varying from twenty-one to twenty-three, very slender. Four 

 gills; laminae elongate, numerous; rakers short, longest one fourth as long 



