FISHES OF HAWAIIAN ISLANDS. 
639 
Peristedion engyceros (Gunther). 
This species has been known hitherto only from the type, which consisted of fragments of a dried 
specimen sent from the Hawaiian Islands to the British Museum. The investigations of the Albatross 
have now shown it to be abundant about the islands on sandy bottom at depths of 150 to 250 fathoms, ' 
about 60 specimens being secured at 17 stations. The following description is based upon this 
material. 
Length of head, measured from front of premaxillaries to opercular margin, 2.5 in length from 
front of premaxillaries to base of caudal; depth 5.75; greatest width of head 3.65. D. vn, 20 (rarely 
21); A. 20; P. 14 + 2. 
The species differs strikingly from P. Ilians in the shape of the rostral processes, which are very 
slender, parallel, of nearly equal width throughout; the distance between them equals their length, and 
is about half length of snout without them; width of the snout opposite anterior nostril equal to 
its length; interorbital space deeply concave, with a median groove, which widens posteriorly; a small 
postocular spine, a much stronger spine at end of occipital ridges, and small spines at end of paroccipital 
opercular crests; upper orbital rim spinulose along its entire length; in the young are usually 2 preor- 
bital spines which disappear in adults; behind snout, the lateral margins of head are expanded to form 
a thin knife-edge, which leads to the long preopercular spine; the anterior limit of the expanded edge 
marked by a projecting spine, to the base of which runs a vertical ridge from front of eye and an oblique 
ridge from middle of lower orbital margin; all the plates of the head minutely prickly; on median por- 
tion of snout 6 or 8 stronger hooked spines, distributed on the rostral ridges; interorbital width 0.65 
diameter of eye, which is contained 4.4 times in head; premaxillaries protruding beyond mandible for a 
'distance equal to 0.2 length of head; length of maxillary contained 2.3 times in head, and equal to the 
greatest external width at angles of mouth; the large barbel, when laid back, extending to base of ven- 
tral fins; along its anterior margin it bears a series of smaller barbels, mostly arranged in pairs; seven 
barbels, similar to these smaller ones, occurring on each side of symphysis, on lower lip and adjacent 
portions of mandible; the most posterior of these, on the mandible, is always paired; mouth toothless; 
gill-rakers 5 + 16 or 17, the terminal ones represented by papillse; spinous dorsal joined to soft dorsal 
at extreme base; pectorals long, reaching fifteenth plate along lateral line, length of upper ray equaling 
distance from tip of snout to front of pupil; upper free ray contained 2.25 times in head. 
Dorsal series of plates with strong backwardly-hooked spines which decrease in size posteriorly, 
almost disappearing on caudal peduncle; behind these 2 movable spines along base of upper caudal 
lobe; the upper lateral series of plates accompanies the lateral line, which opens externally in 3 pores 
for each plate, 1 above and 2 below the spine; behind the short anterior arch the spines are strong; 9 to 
12 spines in front of middle of caudal peduncle bear at the base of the anterior side a short, strong, 
straight spine, directed obliquely forward; spines of ventral row of plates obsolescent, perceptible to 
the touch, but scarcely visible along course of anal fin; only 2 or 3 of the anterior plates of the series 
have well-developed spines. Dorsal series containing 29 or 30 plates, including 2 on base of caudal; 34 
or 35 in upper lateral, 23 or 24 in lower lateral series, and 26 or 27 in ventral series, including 2 on base 
of caudal. 
A specimen in life was pink, with a yellowish tinge, the tips of rostral processes, the fins and long 
barbels deeper pink or almost scarlet, the tips of fins and ends of barbels white; breast and belly white; 
upper parts of head and body marked with fine olive dots and lines, those on head arranged regularly 
and symmetrically; some specimens appear nearly or wholly plain, without spots and lines; pectorals 
whitish, streaked or spotted with olive; anal marked with 3 indistinct narrow yellowish vertical bars; 
other fins unmarked. 
The species was taken at the following stations: Nos. 3919, off the south coast of Oahu, 220 to 257 
fathoms; 3920, off the south coast of Oahu, 265 to 280 fathoms; 3938, vicinity of Laysan, 148 to 163 
fathoms; 3941, vicinity of Laysan, 70 to 146 fathoms; 3957, vicinity of Laysan, 173 to 220 fathoms; 
3986, vicinity of Kauai, 55 to 362 fathoms; 3993, vicinity of Kauai, 201 to 218 fathoms; 4017, vicinity of 
Kauai, 305 to ? fathoms; 4079, off the north coast of Maui, 143 to 178 fathoms; 4080, off the north coast 
of Maui, 178 to 202 fathoms; 4081, off the north coast of Maui, 202 to 220 fathoms; 4082, off the north 
coast of Maui, 220 to 238 fathoms; 4083, off the north coast of Maui, 238 to 253 fathoms; 4115, off the 
west coast of Oahu, 195 to 241 fathoms; 4116, off the west coast of Oahu, 241 to 282 fathoms; 4117, off 
the west coast of Oahu, 253 to 282 fathoms; 4132, vicinity of Kauai, 257 to 312 fathoms. 
Peristethus engyceros Gunther, Proc. Zool. Soc. Lond. 1871, 663; Gunther, Fische der Siidsee, 168 (text figure). 
F.C.B.1903, Pt. 2—5 
