ICHTHYOLOGICAL COLLECTIONS OF THE ALBATROSS. 413 



series of dorsal plates is accoiupanied above by a more or less irregular row of 

 smaller plates, which alternate with the larger plates and bear each a small spine. 



Head 3 to 3^ in length; depth 6. Caudal peduncle long and very slender, its 

 depth less than one-third its length. Maxillary reaching to or nearly to vertical 

 from middle of orbit, 2* to 2f in length of head. Jaws weak ; teeth villiform, with 

 widened base, in moderate bands on jaws, vomer, and palatines. Nasal spines strong, 

 projecting above a transverse depression which crosses snout immediately in front of 

 orbits. Interorbital space narrow ; its least width 3J times in orbit, its width wholly 

 occupied by the two consiDiciious supraorbital mucous canals. Occiput a shallowly 

 depressed pit, bounded anteriorly by the raised orbital region and laterally by low, 

 rounded ridges, each of which terminates behind in a very strong spine. Preopercular 

 spines slender and sharp, the uppermost directed very obliquely upward, sharply 

 notched at tip. The second and third are directed downward and backward, the 

 lowermost downward and forward. The bony stay across cheeks is conspicuously 

 developed, and bears a distinct spine just behind eye. A series of mucous slits 

 along underside of suborbital stay. A sharp spine on subopercle. Gill-membranes 

 broadly united, free from the isthmus, Brauchiostegals, 6. A distinct slit-like pore 

 behind fourth gill. Eye large, 3 in head, longer than snout. Top and sides of head 

 with many minute scattered whitish pores. A minute filament near tip of maxillary. 



Plates of lateral line 43 to 46 in number, their upper and posterior edges free, 

 denticulated. Dorsal series with 45 plates, each of which is crossed obliqviely by a 

 raised spiuy ridge, the central portion of which is highest. Between the upper 

 angles of these plates is a second series of small plates alternating with the first, 

 each bearing a spine or prickle. These spines are occasionally doubled or trebled, 

 especially in the anterior part of the series, and then recall strikingly the arrange- 

 ment in Icelinus. Axil of pectorals with from 20 to 26 plates similar to those of the 

 lateral line and showing a tendency to regular arrangement. Two or three similar 

 plates along anterior part of base of anal, and a few scattered plates on each side 

 between lateral and dorsal series. 



Dorsal vii or viii, 23 or 24 ; anal 19 ; pectoral 16 ; ventral i, 3. Lateral line 43 to 

 46. Length 110 mm. 



Color: Light olivaceous above, blackish below, except lower jaw; back with four 

 black crossbars, evident but not conspicuous. Opercles black. Fins all dark. Pecto- 

 rals mottled with slate color. Base of caudal tin light. Mouth and gill-cavity dark. 



The types were taken north of Unalaska, at station 3329, at a depth of 399 

 fathoms. 



54. Icelus vicinalis sp. nov. 



This species is extremely close both to /. canaliculatus, with which it was found 

 associated, and to I. euryopa Bean. From I. canaliculatus it differs in the following 

 respects : 



(a) The coloration, though similar in pattern, is much lighter. The belly is 

 dusky, but not deep brown; the isthmus usually beco-mes abruptly white under 

 the branchiostegal membranes, and the latter are white or dusky, not blue-black as 

 in I. canaliculatn.s. The floor and anterior part of the roof of the mouth and the 

 gill-cavities are white, not blackish. The nostril tube is white, not black. 



(b) The occipital ridge is lower and less conspicuous and the spines shorter, but 

 both are obvious. The small spinous point on suborbital stay is less developed. 



(c) The dorsal spines are 9 in number in all our specimens. 



(d) A closely crowded series or narrow band of prickles accompanies the dorsal 

 series, as in /. canaliculatus. It is noticeable, however, that those of the series which 

 occupy a position corresponding to the interspace between the dorsal plates are 

 somewhat enlarged, and recall the alternating plates of Icelinus. The region 

 between the lateral line and the dorsal series is almost completely invested with 

 spinous scales in most specimens, while in /. canaliculatus few or none are present. 



