522 BULLETIN OF THE ITNITED STATES FISH COMMISSION.
Hemirhamphidae.
46. Hyporhamphus pacificus (Steindachner). Laysan Island.
47. Hemiramphus depauperatus Lay & Bennett. Honolulu; station 3834, southern coast of
Molokai, depth 13 fathoms.
48. Euleptorhamphus longirostris (cuvier). Honolulu.
Exocoetidae.
49. Exocoetus volitans Linnaeus.
An example came aboard ship at night somewhere between stations 3804 and 3805, about 24° N. by 151° W.; another at station 3808, near Oahu. These have not been compared with specimens from the Atlantic. The ventrals are inserted midway between tip of snout and base of eighth ray of anal in one individual; between snout and tenth ray in the other. The pectorals extend to the base of the caudal; the first ray simple, the second divided, the third forming tip of fin. The dorsal and anal each have 13 rays, the former inserted immediately above the latter; base of anal longer than that of dorsal by an amount equal to space between the two posterior rays. The length of the ventrals is 0.56 of the base of anal. There are 35 scales in a series between upper edge of base of pectoral and the caudal, 21 or 22 between occiput and dorsal fin. Head measured to end of opercular 'flap equals 0.25 the length; snout 0.22 of head, including opercular flap; eye 0.31; interorbital space 0.35. The pectorals are dusky with a light posterior margin. Dorsal, anal, and ventrals without color.
50. ParExocoetus brachypterus (Solander). Honolulu; station 3829, off southern coast of Molokai.
51. Exonautes gilberti Snyder, new species. Plate 7, fig. 13.
.Head, to end of opercular flap, 0.215 of length; depth 0.147; width of body at base of pectorals 0.145; depth of caudal peduncle 0.28 of head; eye 0.32; snout 0.28; interorbital space 0.38; D. 10; A. 10; scales in lateral series beginning above base of pectoral 48; between occiput and base of dorsal 32; between lateral line and dorsal 6.
As indicated by the above measurements of the body, this is one of the most slender of the flying fishes. Body quadrangular in section; back broader than belly, convex; some of the median scales of back with low keels; interorbital space conclave; snout a little shorter than diameter of eye; lower jaw slightly projecting beyond upper; maxillary extending to posterior border of nostril. No teeth on tongue or roof of mouth, those on jaws scarcely perceptible; gillrakers on first arch 25, long and slender; lateral line disappearing near end of anal fin.
The pectoral fin extends to within about an eye's diameter of base of caudal; of 18 rays, first and second simple; second a third of its length longer than first, which is 3.81 times diameter of eye; third ray divided near tip of first; tip of fin formed by branches of fourth ray, those of fifth being slightly shorter; second ray of dorsal fin longest, 0.52 of head; base of fin equal to 2 times diameter of eye; anal inserted the width of a scale posterior to dorsal, its base shorter than that of dorsal by an amount equal to the space between 2 rays; height of first and second rays about equal to that of fourth dorsal; ventrals inserted midway between base of caudal and a point anterior to edge of opercle, a distance equal to diameter of pupil; extending posteriorly a little beyond the base of anal, not beyond tip of last ray when depressed. Upper lobe of caudal pointed, its length 3 times the width of the interorbital space; lower lobe an eye's diameter longer.
Color in alcohol, dark brown above, silvery below, pectoral without spots, dusky; the free edge with a white area as wide as pupil, proximal to which is a blackish band two-thirds as wide as the eye; upper or anterior edge of fin light, an indistinct dark area extending along the first to fourth rays; lower or posterior edge of fin along the last four rays white. Middle rays of ventrals dusky, the fin indistinctly bordered with white. Free edge of caudal bordered with white. Dorsal dusky; anal white.
In life, steel blue above, silvery below.
The species is seemingly related to Exonautes rondeletii (cuvier & Valenciennes) of the Atlantic.
It is represented by one individual 26.5.centimeters long (snout to end of lower caudal lobe), which came aboard the Albatross at night, between stations 3799 and 3800, somewhere near 28i° N. by 140° W.
Type, No. 50872, U. S. Nat. Mus.
Named for Dr. Charles Henry Gilbert.
52. Cypsilurus simus (cuvier & Valenciennes). Honolulu; Waimea and Hanamaula Bay, Kauai;
station 3860, Napili, Molokai.