FISHES OF HAWAIIAN ISLANDS. 
663 
The stomach contains remains of small shrimp-like Crustacea, and the eyes and jaws of squids. 
Specimens were taken at the following stations: Nos. 3865, Pailolo Channel, 256 fathoms; 3867, 
Pailolo Channel, 284 to 290 fathoms; 3908, off the south coast of Oahu, 304 to 308 fathoms; 3910, off 
the south coast of Oahu, 311 to 337 fathoms; 3911, off the south coast of Oahu, 334 to 337 fathoms; 
3914, off the south coast of Oahu, 289 to 292 fathoms; 3916, off the south coast of Oahu, 299 to 330 
fathoms; 3917, off the south coast of Oahu, 294 to 330 fathoms; 3918, off the south coast of Oahu, 257 
to 294 fathoms; 3920, off the south coast of Oahu, 265 to 280 fathoms; 4025, vicinity of Kauai, 275 to 
368 fathoms; 4084, off the south coast of Maui, 253 to 267 fathoms; 4085, off the south coast of Maui, 
267 to 283 fathoms; 4086, off the south coast of Maui, 283 to 308 fathoms; 4087, approach to Pailolo 
Channel, 306 to 308 fathoms; 4088, approach to Pailolo Channel, 297 to 306 fathoms; 4089, approach 
to Pailolo Channel, 297 to 304 fathoms; 4090, approach to Pailolo Channel, 304 to 308 fathoms; 4097, 
approach to Pailolo Channel, 286 fathoms; 4117, off the northwest coast of Oahu, 253 to 282 fathoms; 
4122, off the southwest coast of Oahu, 192 to 352 fathoms; 4130, vicinity of Kauai, 283 to 309 fathoms; 
4134, vicinity of Kauai, 225 to 334 fathoms. 
Chalinura ctenomelas Gilbert & Cramer, Proc. U. S. Nat. Mus., XIX, 1897, 430, pi. xlv, fig. 2. 
Optonurus atherodon. Gilbert & Cramer. 
One of the most abundant species of Hawaiian Macrurids between 250 and 400 fathoms. 
The original description may be amended in the following respects: Ventral fins with 9 or 10 
rays; snout short, projecting but little beyond mouth, its length contained 1.2 times in orbit, its pre- 
oral portion 3 to 4 times in orbit; median rostral ridge ending freely between orbits, not joining a 
transverse ridge, a delicate, thread-like cord connecting it with orbital margin; the small curved 
ridges on occiput, mentioned in the description of the type, are delicate long spicules bridging the 
excavated space between occiput and orbital margin; maxillary extending well behind middle of 
orbit, to a vertical line intersecting eye midway between pupil and posterior border of orbit; posterior 
margin of preopercle extending somewhat obliquely upward and forward; barbel about 0.3 length of 
orbital diameter; all the teeth in both jaws are distinctly arrow-shaped at tip; premaxillary villiform 
band about 6 teeth wide; mandibular band consisting of an inner irregular series of slightly enlarged 
teeth, and an outer irregular series of smaller teeth, both series terminating at the same point 
laterally. 
Interspace between dorsal fins 2.5 times the base of anterior dorsal; pectorals 0.6 the length of 
head; pyloric caeca 97 in the single specimen examined as to this point; a distinct, small, naked pit 
between bases of ventral fins, separated by a narrow band of scales from the naked area around vent. 
The food consists of shrimp-like Crustacea and squid. In life, the dorsal region is bright blue. 
Taken at the following stations: Nos. 3867, Pailolo Channel, 284 to 290 fathoms; 3884, Pailolo 
Channel, 284 to 290 fathoms; 3910, off the south coast of Oahu, 311 to 337 fathoms; 3912, off the south 
coast of Oahu, 310 to 334 fathoms; 3914, off the south coast of Oahu, 289 to 292 fathoms; 3917, off the 
south coast of Oahu, 294 to 330 fathoms; 3918, off the south coast of Oahu, 257 to 294 fathoms; 3979, 
vicinity of Bird Island, 222 to 387 fathoms; 3988, vicinity of Kauai, 165 to 469 fathoms; 4021, vicinity 
of Kauai, 286 to 399 fathoms; 4025, vicinity of Kauai, 275 to 368 fathoms; 4041, off the west coast of 
Hawaii, 253 to 382 fathoms; 4085, off the north coast of Maui, 267 to 283 fathoms; 4086, off the north 
coast of Maui, 283 to 308 fathoms; 4087, off the north coast of Maui, 306 to 308 fathoms; 4089, off the 
north coast of Maui, 297 to 304 fathoms; 4090, off the north coast of Maui, 304 to 308 fathoms; 4091, off 
the north coast of Maui, 306 to 308 fathoms; 4097, off the north coast of Maui, 286 fathoms; 4107, 
Kaiwi Channel, 350 to 355 fathoms; 4122, off the southwest coast of Oahu, 192 to 352 fathoms; 4123, off 
the southwest coast of Oahu, 352 to 357 fathoms; 4130, vicinity of Kauai, 283 to 309 fathoms; 4137, 
vicinity of Kauai, 411 to 476 fathoms; 4139, vicinity of Kauai, 339 to 512 fathoms. 
Optonurus atherodon Gilbert & Cramer, Proc. IT. S. Nat. Mus., XIX, 1897, 431, pi. xlvi, fig. 1. 
Hymenocephalus antrseus Gilbert & Cramer. 
The most abundant Macrurid about the Hawaiian Islands in depths of 250 to 350 fathoms, where 
it occurs in company with Chalinura ctenomelas , Optonurus atherodon, and Malacocephalus hawaiiensis. It 
is much smaller than either of these species, reaching a length of only 20 centimeters, and is charac- 
terized by the excessive development of the sensory canals, which are covered by a very delicate mem- 
