676 KIU.LETIN l»K THE IFNITED STATES FISH COMMISSION. 



cm lieuil low but lUiitiiK-t, the iiiiiL-r pair on occ-iput coiivergini; posteriorly, then again slightly diverg- 

 ing. IMeiliun rostral riilge incouspicuout;; the stioiig infraorbital ridge ends posteriorly in a short 

 strong siiine, bcyund wliirli jirojeets the soft nu'niljraiious margin of the preopercniar lolie; upper limb 

 of preiiperele gently roncavt' in its lowei- half, gently convex in the upper; transverse width of mouth 

 at tips (if maxillaries equal to Dji widtli of snout at same level; front of mouth opposite anterior nostril; 

 till of maxillary reaching a point opposite posterior margin of pupil; length of maxillary 0.7 preoral 

 portion of snout; teeth small, in wide hands in each jaw, none of them enlarged; barbel very slender, 

 half diameter of pupil; gill-membranes forming a very narrow free fold across throat; 9 tubercles 

 rejiresi'iit gill-rakers on outer ari'h. 



First dorsal tin inserted directly above axil of pectoral; .second dorsal spine smooth throughout an<l 

 very slender and weak, the distal half as flexible as a ray, its length equaling 0.7 that of snout; the 

 distance between dorsals equals base of anterior dorsal without its spines, and is crossed by )-! series of 

 scales; anal originating under second or third ray of second dorsal; inner base of \'entrals midway 

 l)et\\een \ent and edge of brani-liial meiidirane on median line; ventral lilanient reacliing vi'Ul; 

 pectorals reach to a jxiint ojijiosite origin of anal tin. 



Scales of back and sides each with a median ridge composed of imbricating spines, which in<Tease 

 regularly in length posteriorly, the last one projecting little if at all beyond margin of scale; also from 1 

 to (i pairs of similar but very low parallel lateral ridges, which never ap[)roximate in size to the central 

 ridge, and rarely reacli margin of scales; spination much weaker than in piiralMxs or ariilnuii: on 

 breast and alidounnal regions, tlie lateral .series are much stronger than on liaek and sides, and are still 

 parallel or nearly so; scales on head without spines, Imt roughened with mimite prii'kles, which are 

 arranged in more or less evident radiating or stellate .series; a naked area is evident <m nnddle of occiput, 

 where the scales fail to meet; naked lines also follow along the ridges, and between nas:d bones and 

 rostral ridge; nasal fossa nearly as large as jnipil; lower side of head wholly naked, except for a small 

 patch of prickles near ti]i of snout; ^ series of scales between lateral line and second dorsal lin; hi 

 scales in a series upward and backward from vent to lateral line. 



Color very light gray, all the fins, including ventral filament, black thioughout; ternnnal jiortion 

 of snout and lowci' side of head blai'kisli; lining of mouth, gill-cavity, and ])eritoneum black, very 

 faintly visit le externally. 



In young siieciinens, iL'.'i nun. long and less, ap]iarently belonging to this sjiecies, the scales on 

 liack and sides are es.sentially similai' to tlii>se in ailults, both median and lateral .seiies of spines being 

 [iresent. and in about the same relative size. The <'e]ilialic ridges seem proportionally high(-r and 

 are strongly spinous, including a median rostral ridge winch loses its ])rominence in adults; but the 

 intervening areas on head, as well as the breast and belly, are covered with smooth cycloid scales, a 

 few only showing a series of median spines. Specimens less than 100 nun. long are marked liy a series 

 of 10 to 1.") small black spots along base of anal fin. 



Taken at th.' following stations: Nos. 4021, oft the east coast of Kauai, 280 to :W9 fathoms; 4109, 

 Kaiwi Channel, 442 to 440 fathoms; 4112, Kaiwi Channel, 433 to 447 fathoms; 4122, off the southwest 

 coast of Oahu, 102 to :!.'i2 fathoms. 



Matffiocephalus acipeiiserinus (< iilbert i>v: Cramer). 



A very abundant species at <lepths lietween 200 and 400 fathoms. The following details may be 

 added to the original description of the species. 



Lateral margins of head angulated at a point immediately in fiMiit of nostrils, in front of which the 

 contours converge much more rapidly. In this anterior segment of the snout, the lateral margin, is soft 

 and nrembranous, with skeletal basis, but is thickened and I'overed with conrjiaratividy large s]:iinous 

 scales; suborbital bone weakly spirmlo,se; as it fails to join pr-eoperi4e behind, it is less firmly fixed 

 than usual; occipital regiorr evenly r'oumled, without trace of the spinous riilges so corrs]iicnous in 

 species of < 'iiliirliiinrliiix. Mcnitli very small, the width posteriorly lint 0..", the width nf head on same 

 line. 



Two types of colonttion appear' irr oirr s|)ecimens. Some are uniform pale br-own on upper parts, 

 a.« irr the type, others base a pale spot at base of each scale ioiuiing rather definite longitudirral 

 streaks aliovi- lateral lirrc. Irr these si>ecimens, the top of head anil the first doi'sal finale .sjiolted or 

 niotlled wilh dark. 



