BULLETIN OF THE UNITED STATES FISH COMMISSION. 
336 
This is one of the most abundant and beautiful fishes found among the Hawaiian Islands. It 
appears to be related to II. melcinopus of Bleeker, but differs from it markedly in the presence of the 
large black lateral blotch and in the absence of the large red lateral blotch shown in Bleeker’ s figure. 
The collection contains 42 excellent specimens, 40 from Honolulu and 2 from Hilo, ranging in length 
from 5.75 to 8.8 inches. 
Hemipteronotus baldwini Jordan & Evermann, Bull. U. S. Fish Comm., XXII, 1902 (April 11, 1903), 192, Honolulu. 
266. Hemipteronotus jenkinsi Snyder. Plate 42, fig. 2. 
Head, including opercular flap, 3.5 in length; depth 2.8; depth of caudal peduncle 2.2 in head; 
eye 6; width of interorbital space 5; length of maxillary 3; D. ix, 12; A. iii, 12; lateral line 22+6. 
Eye located 2.66 times its diameter above angle of mouth; mouth nearly horizontal, on a level 
with upper edge of base of pectoral, the maxillary extending to a vertical through anterior edge of 
orbit; lower jaw slightly longer than upper; lips with rather thin, fleshy folds; outer row of teeth 
strong, conical, those on sides of jaws posterior to canines gradually decreasing in size from before 
backward; canines curving outward and forward, the lower pair, which are slightly the larger, fitting 
between the upper ones; inner teeth short and blunt, in narrow bands; pseudobranchke present; 
gillrakers on the first arch 6+11, short and sharply pointed; edge of preopercle smooth. 
Plead naked, except for a narrow, vertical, scaled area extending downward from eye to a hori- 
zontal passing along edge of flap of upper lip; first row with 7 scales, curving upward behind eye; 
second row with 5, the third with 4; scales of breast about half as large as those on sides of body; 
scales 2-27-9; lateral line curving upward over first 6 scales, then following the dorsal contour, 
approaching the back near end of dorsal, discontinued after twenty-second scale, beginning again on 
third scale below and passing along middle of caudal peduncle; first 2 dorsal spines somewhat closer 
together than others, but not separated from them, the membrane being continuous; height of first 
spine 2.6 in head, the second shorter; remaining spines 4 in head; height of rays 2.9; end of soft dorsal 
when depressed just reaching base of caudal fin; anal spines small and slender, the rays equal in 
height to those of the dorsal; base of anal and also the tips of the rays when depressed extending 
farther posteriorly than corresponding parts of dorsal; caudal rounded, the basal fourth with scales, 
the length 1.6 in head; pectoral 1.5; outer rays of ventral filamentous, just reaching vent. 
Color in spirits, head plain, without spots, bars, or lines; a conspicuous black spot on back cover- 
ing 2 scales above sixteenth in lateral line, its distance behind the opercular flap equal to distance 
between that point and tip of snout; a yellowish white spot on side of body, rather indistinctly out- 
lined, covering an area equal to width of 5 scales and height of 3 or 4, the spot partly covered by 
pectoral when depressed; scales of body, except on breast, belly, and part covered by the large light 
spot, each with a vertical pearly bar which grows wider on the ventral scales, covering over half the 
scale in region above base of anal; soft dorsal and anal with oblique dark bars, those of the anal not so 
broad as those of dorsal; caudal, pectorals, and ventrals plain. 
This species is said to be readily distinguished from closely related Hawaiian forms by the great 
depth of the body and by the small dark spot, the posterior location of which is notable, but it seems 
to be a young female of II. baldwini. 
Known only from the type, a specimen 1 inch long from Puako Bay, Hawaii. 
Hemipteronotus jenkinsi Snyder, Bull. U. S. Fish Comm., XXII, 1902 (Jan. 19, 1904), 530, pi. 10, fig. 19, Puako Bay, Hawaii 
(type, No. 50879, U. S. N. M. Coll. Albatross). 
Genus 167. XYRICHTHYS Cuvier & Valenciennes. 
Body short, deep, and very greatly compressed; anterior dorsal outline parabolic and very trenchant; 
cheek scaleless; lateral line interrupted; first 2 dorsal spines removed but not detached from the third, 
the membrane between the second and third being moderately notched. 
Xyriehthys Cuvier & Valenciennes, Hist. Nat, Poiss., XIV, 33 1839 (cultratus). 
Xyrichthys Gill, Proe. Ac. Nat. Sci. Phila. 1862, 143 ( mundieeps ). 
