ICHTHYOLOGICAL COLLECTIONS OF THE ALBATROSS. 439 
Color lighter than in X. pentacanthus, more or less finely speckled above, usually 
' with five or six dusky crossbars on back. A series of linear dark blotches below 
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the lateral line. The head is often finely speckled with brown and shows traces of 
a brown bar forward from eye to snout. Dorsals, caudal, and upper half of pectoral 
light, finely speckled with brown, the caudal shaded with dusky. Ventrals and 
anal white. 
Taken rather abundantly in the vicinity of Unimak Pass, both north and south 
of the islands, at depths of 35 to 138 fathoms. Stations 3216, 3219, 3223, 3225, 3226, 
3257, 3258, 3263, 3309, 3310, 3311, 3313, 3322, 3334, 3336, and 3339. 
88. Bathyagonus nigripinnis Gilbert. 
In adult specimens the lower pectoral rays show a tendency to elongate, as in 
Xenochirus, but the fin is never distinctly notched. The lower jaw always strongly 
protrudes, and the genus differs further in the very thin cranial bones and the inor- 
dinate development of the mucous system. In addition to the specific characters 
mentioned in the original description, we note that the eyeball does not exhibit the 
usual row of prickles, and that two barbels are usually present at end of maxillary, 
either black or white in color. 
The skull is firmer than indicated in the original description, the mucous channels 
less conspicuous. Eye 3 in head. Interorbital width 3 in orbit. Anterior part of 
supraorbital ridge strongly flattened and finely rugose. One occipital spine only. 
In life, the body is translucent-grayish, the fins blackish, the lower side of head, 
the belly, the anal fin, and the lower pectoral rays bright blue with golden reflections. 
The majority of the specimens were obtained north of Unalaska Island; it was 
also taken south of the islands, and off the coast of Washington. Stations 3210, 
3316, 3324, 3325, 3329, 3330, 3331, 3332, 3337, and 3343; depths 109 to 483°fathoms. 
89. Hypsagonus quadricornis (Cuvier & Valenciennes). 
Taken north and south of the Aleutian Islands in shallow water; also at one 
station in Bristol Bay. Stations 3213, 3214, 3217, 3220, 3223, 3224, 3262, and 3322; 
depths from 34 to 121 fathoms. 
Our specimens agree perfectly with the description of Hypsagonus (Cheiragonus) 
gradiens Herzenstein (Bull. Acad. Imp. des Sci. de St. Petersburg, x111, 116, May 29, 
1890) described from the Gulf of Awatscha in Kamchatka. Dr. G. A. Boulenger, 
of the British Museum, has kindly compared one of our specimens with the type of 
Aspidophorus quadricornis Cuvier & Valenciennes, and states that they are undoubt- 
edly identical. 
Body short, much compressed, the head also narrow and compressed, especially 
above and infront. Nasal spines short and strong, a slender barbel of varying 
length in front of them on middle line of snout. Ocular region abruptly rising 
above the short slender snout, the eyes vertical, overarched by the supraorbital rim 
which bears posteriorly a strong vertical spine. Interorbital space with a deep 
median groove and without ridges, the occipital region depressed below the bottom 
_of the groove. No deep pit on occiput, the space being gently concave transversely, 
bounded laterally by moderate ridges, which bear posteriorly a spine preceded by a 
long tubercle. A strong spine at lower inferior border of orbit. A strong spine at 
_ upper preopercular angle and three smaller ones belowit. A strong spine above the 
base of pectoral, behind and above which on sides are two strong spines nearly in 
_ line with the upper lateral series of plates. Surface of opercles with a few short 
spinous processes, but without definite spine. Vomer and palatines toothless. 
Branchiostegal membranes broadly joined, forming a free fold across the isthmus. 
, Mouth narrow, horizontal, terminal, the lower jaw included. Maxillary reaching 
vertical slightly behind front of orbit, 3} in head. Eye large. 3 in head; snout 4; 
_ interorbital width over middle of orbit, + head behind snout. 
Nape rising very abruptly from occiput to front of dorsal, the outline thence 
descending to near front of second dorsal, when it again ascends. The points of 
