738 Bulletin 47, United States National Museum. 



simple) ; third and fourth, rays longest ; ventral fins inserted midway 

 between posterior margin of preopercle and last caudal vertebra ; pecto- 

 rals not uniformly colored ; posterior half of pectorals, ventrals, and 

 dorsal rather abruptly black ; anal white. Length of pectoral fin \\ in 

 body, its tip reaching nearly to base of caudal ; first ray of pectoral 

 If in length of longest; ventrals 2f in length of body, their tips reach- 

 ing tip of last ray of anal; dorsal rather high, its longest rays \\ in 

 head; longest anal ray 3 in head, lower lobe of caudal about \ longer 

 than head. Interorbital space broad, slightly concave, its width 2 

 head; depth of head If in its length. Length 10 inches. Tropical 

 seas, north to Cuba, Central America, and France; not very common; 

 recognizable at once by its high dorsal, black on the anterior half. 

 The specimen here described was from the Open Atlantic off Brazil. 

 (nigricans, blackish.) (Eu.) 



Exoccetus nigricans, BENNETT, Whaling Voyage, n, 287, 1840, ' ' taken in both the Atlantic and 

 Pacific Oceans, in lat. 5 N."; GUNTHEB, Cat.,vi, 290, 1866; JOEDAN & MEEK, I c., 63. 



Exoccelus bicolor, CUVIER & VALENCIENNES, Hist. Nat. Poiss., xix, 111, 1846, Atlantic. 



Exoccetus spilopus, CUVIEE & VALENCIENNES, Hist. Nat. Poiss., xix, 118, 1846, La Rochelle; 

 St. Helena; West Indies; India; Arabia; De Witt Land; GUICHENOT, Hist. Cuba, 

 Ramon de la Sagra, Poiss., fig. 2, 1853, 152, pi. 4; LUTKEN, Vid. Med. Naturh. Foren., 

 107, 1876. 



1089. EXOCCETUS XENOPTERTJS, Gilbert 



Head 41; depth 6. D. 13; A. 10; scales about 45. Snout short, 3| in 

 head ; mandible scarcely protruding, wide at tip, with a narrow band of 

 small teeth. Teeth along edge of premaxillaries in a single series. 

 Vomer with a narrow patch, palatines with a wide patch of well- 

 developed teeth, similar to those in jaws ; no teeth on tongue. Pre- 

 orbital about as wide as pupil ; distance from tip of snout to end of 

 maxillary equals length of snout. Eye large, 3 in head. Interorbital 

 width 3 in head. Distance from front of dorsal to base of middle of cau- 

 dal rays equals half its distance from posterior margin of pupil. Length 

 of dorsal base equals f length of head, the highest ray 2f in head. 

 Origin of anal under middle of dorsal, its base equaling snout and half 

 eye, the last ray nearly under last dorsal ray. Lower lobe of caudal 3^ 

 in length ; the upper slightly less than head. Origin of ventrals half- 

 way between base of caudal and preopercular margin, the tip reaching 

 base of third anal ray, a trifle shorter than head. First pectoral ray | 

 the longest; second ray deeply forked, the third and fourth apparently 

 the longest (the tips slightly mutilated). The fin extends beyond dorsal, 

 and falls short of the caudal by a trifle. Black above, becoming 

 abruptly silvery on middle of sides; pectorals jet black within, overlaid 

 by some silvery luster without; median ventral rays black, the inner 

 and outer white ; dorsal dusky, without distinctive marks ; anal white ; 

 caudal black on basal portion of both lobes, the remaining third white. 

 A single specimen, 9| inches long, taken from a booby-bird (Sula) on 

 Clarion Island, one of the Revillagigedos. (vof, strange; irrcpov, fin.) 

 Exocoetus xenoptems, GILBERT, Proc. U. S. Nat. Mus., 1890, 58, Clarion Island. (Type, No. 

 44388, Coll. Albatross.) 



