1916 Bulletin 47, United States National Museum. 



lateral line and dorsal series; a patch of spinous plates behind pectorals. 

 Color evidently as in Icelus vicinalis, though very greatly faded from 

 exposure to light; the back shows traces of 2 dark cross bars under soft 

 dorsal; 1 occupies end of caudal peduncle, and a very indistinct one 

 extends downward from spinous dorsal which is black posteriorly ; belly 

 and under parts generally dusted with fine black specks, the isthmus 

 becoming abruptly white; nostril tube white; subocular region blackish, 

 the color continued forward into the preorbital, opposite the front end of 

 which it crosses upper and lower lips; a dark blotch on maxillary in 

 advance of tip; pectorals dusky, (svpvg, wide; wi{>, eye.) 



Icelus euryops, BBAN, Proc. U. S. Nat. Mus. 1890, 41, off Trinity Islands, at Albatross 

 Station 2853. (Type, No. 45367, U. S. 1ST. M.) 



2294. ICELUS VICINALIS, Gilbert. 



Head 3| to 3i; depth 5f. D. IX, 21 to 23; A. 18; P. 16; C. 9. This 

 species is extremely close both to Icelus canaliculatus, with which it was 

 found associated, and to Icelus euryops, Bean. From Icelus canaliculatus 

 it differs in the following respects : The coloration, though similar in pat- 

 tern is much lighter. The belly is dusky, but not deep brown; the isth- 

 mus usually becomes abruptly white under the branchiostegal membranes, 

 and the latter are white or dusky, not blue black as in Icelus canaliculatus. 

 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. The occip- 

 ital ridge is lower and less conspicuous, and the spines shorter, but both 

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

 The dorsal spines are 9 in number in all our specimens. A closely crowded 

 series or narrow band of prickles accompanies the dorsal series as in Icelus 

 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 com- 

 pletely invested with spinous scales in most specimens, while in Icelus 

 canaliculatus few or none are present. The head is densely covered with 

 small spinous scales or prickles especially numerous on top of head, and 

 on opercle. In Icelus canaliculatus the head is either naked or sparsely 

 covered and the opercles almost or quite naked. Three pairs of slender 

 filaments on top of head, the anterior pair the largest, placed above back 

 of orbit; the second pair in front of and slightly within the occipital 

 ridges, the third pair on occipital spines. An additional pair on opercles 

 seems to be less constant. The supraocular pair alone is present in led us 

 canaliculatus. The mucous canals and pores, though large, are less devel- 

 oped than in Icelus canaliculatus, the fish having, in general, the bathybial 

 characteristics less pronounced. The agreement with Icelus euryops is 

 closer than with Icelus canaliculatus. In fact, it seems to differ from Icelus 

 euryops only in the much smaller eye and the somewhat wider interorbitai 

 space, agreeing with Icelus euryops in all those respects in which it differs 

 from Icelus canaliculatus. In Icelus vicinalis the eye is 2| to 3 in head, and 



