ICHTHYOLOGICAL COLLECTIONS OF THE ALBATROSS. 439 



Color lighter than in X. jyentacanthus, more or less finely speckled above, usually 

 with five or six dusky crossbars on back. A series of linear dark blotches below 

 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 upperhalf 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 si)ecific characters 

 mentioned in the original description, we note that the eyeball does not exhibit the 

 usual row of prickles, and that two barl)els 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. luterorbital 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 Herzensteiu (Bull. Acad. Imp. des Sci. de St. Petersburg, xiii, 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 in front. 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 bj' the supraorbital rim 

 which bears posteriorly a strong vertical spine. luterorbital space with a deep 

 median groove and without ridges, the occipital region depressed below the bottom 

 of the groove. No dee^} 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 below it. 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 broadlj' 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 



