210 MEMOIRS OF THE CARNEGIE MUSEUM. 
Family MICROSTOMATID®. 
18. Nansenia ardesiaca Jordan & Thompson, sp. nov. (Plate XXIV, fig. 2.) 
( Nansenia grenlandica Tanaka, non Reinhardt.) 
This species is well figured by Tanaka. 
Description of a specimen (No. 6023a) 190 mm. in total length, taken in 
three hundred and fifty fathoms at Okinose, in Sagami Bay, Alan Owston collection: 
Head 4.5 in body, 5 in total length; body-depth 8 in body-length; eye 2.33 in 
head; snout 6.5; maxillary 4.5; interorbital space 4; dorsal rays 10; anal 10; pec- 
toral 12; ventral 12; scales in lateral line 55 (five of which are on caudal) ; from center 
of breast to middorsal line 8 (counting lateral line); gill-rakers 12+ 25. 
Body elongate, subcylindrical, greatest depth from between posterior margin 
of eye to insertion of dorsal fin; caudal peduncle half this depth. Eyes very large, 
projecting somewhat above dorsal profile of head and approaching ventral profile; 
snout very short and blunt; lower jaw somewhat projecting; mouth opening ob- 
liquely; line of maxillary approaching vertical; maxillary covered by anterior end 
of pre-orbital, reaching slightly behind anterior margin of eye; teeth small, conical, 
in a single rather thick-set row in each jaw, none enlarged or canine-like; vomer and 
palatines toothless; interorbital space broad, concave; suborbital and opercular 
bones thin and flexible; latter with emargination above angle, leaving open passage 
to gill-cavity. 
Dorsal fin inserted slightly before middle of distance between snout and base 
of caudal, its base half the length of the fourth ray, which is equal to the distance 
from the tip of snout to posterior border of eye; ventrals inserted slightly behind 
last dorsal ray, length equal to fourth dorsal ray; anal inserted nearer caudal base 
than tips of ventrals, longest ray less than diameter of eye; pectorals narrow, first 
and twelfth rays simple, others branched, longest ray 1.75 in head; adipose fin 
small, inserted above posterior half of anal fin, its length 2.33 in eye. Caudal 1.5 
in head, forked, but not deeply. 
Scales large, thin, loosely attached; base of scales coarsely serrate, each basal 
radius projecting; circuli parallel to serrated edges, forming acute angles to cor- 
respond to teeth of base; circuli very fine and numerous. Tube of lateral line very 
large, its breadth a fourth of that of its scales; pores large, single; lateral line con- 
tinued beyond base of caudal as an appendage formed of six or seven successive 
scales and attached only at the base to caudal ray. Lateral line tube continued 
over dorsal surface of head to snout, over the occiput and along lower margin of eye. 
Color brilliant silvery; dusky on snout, jaws, opercular plate, and bases of 
caudal and ventrals; scales of a bright, silvery appearance. Along the center of 
