720 Bulletin 47, United States National Museum. 



belly. Upper jaw short; lower jaw prolonged into a slender beak, bor- 

 dered with membrane; this beak shorter in the young; premaxillaries 

 forming a triangular plate, the teeth of which fit against the toothed por- 

 tion of the mandible ; maxillaries joined to premaxillaries. Teeth feeble, 

 mostly tricuspid. Gill rakers rather long. Head covered above with 

 large, shield-like scales. Scales large, deciduous. No finlets ; caudal fin 

 more or less forked, the lower lobe the longer ; dorsal and anal similar, 

 opposite each other, not modified in the males ; last ray of dorsal usually 

 short; ventrals small, inserted well forward, nearly midway between 

 opercle and base of caudal. Oviparous. Air bladder large, simple, not 

 cellular. Young with the lower jaw short. Sides in our species with a 

 distinct silvery band, as in Atherina. Species numerous, in all warm seas, 

 going in large schools, but usually remaining near shore, feeding chiefly 

 on green algse. Size comparatively small. (I^TTO, below ; pd/uQog, beak.) 



a. Ventrals inserted about midway between posterior margin of eye and base of caudal; dor- 



sal and anal scaly; scales 53 to 56. 



b. Length of mandible from tip of upper jaw less than rest of head in adult; (longer in 



young); body rather stout; D. 15; A. 16. UNIFASCIATUS, 1069. 



bb. Length of mandible from tip of upper jaw not less than rest of head, at all ages; 



much greater in adult; body more slender. D. 14; A. 15. ROBERTI, 1070. 



aa. Ventrals inserted at a point nearly, midway between gill opening and base of caudal; dorsal 



and anal with very caducous scales or none; scales 63 in a longitudinal series. D. 14; 



A. 14; form rather slender; beak longer than rest of head. ROB.E, 1071. 



1069. HYPORHAMPHUS UNIFASCIATUS (Eanzani). 



(ESCR1BANO.) 



Head 4{? ; depth about 6. D. 12 to 14 ; A. 15 ; scales 52 ; vertebrae 34 + 

 18 = 52. Very close to H. roberti, differing chiefly in the shorter beak 

 and the less compressed and more robust body. Lower jaw from end of 

 upper jaw 6 to 7 in total length from its tip to base of caudal (4i in H. 

 roberti), its length in adult always less than that of rest of head; young 

 with the beak proportionately longer; head with lower jaw 3 in body; 

 body half deeper than broad ; premaxillary plate broader than long ; eye 

 less than interorbital width, f postorbital part of head ; ventrals midway 

 between eye and base of caudal ; dorsal and anal densely scaly ; back 

 broad. Length 1 foot. West Indian fauna, generally common from Key 

 West to Rio de Janeiro ; also taken at Panama ; this or some very similar 

 species also in the East Indies and on the coast of Africa. The young of 

 this species has the beak longer and can not always be readily distin- 

 guished from Hyporhamphus roberli, which is, however, always more slen- 

 der ; here described from Key West specimens, (unus, one ; fascia, band.) 



Hemirhamphus unifasciatus, RANZANI, Nov. Comm. Ac. Sci. Bonon., v, 1842, 326, Brazil; GUNTHER, 

 Cat., vi, 262, 1866; MEEK & Goss, Proc. Ac. Nat, Sci. Phila., 1884, 222. 



Hemirhamphus picarti, CUVIER &.VALENCIENNES, Hist. Nat. Poiss., xix, 25, 1846, Algiers. 



Hemirhamphus richardi, CUVIER & VALENCIENNES, Hist. Nat. Poiss., xix, 26, 1846, Antilles; 

 Cayenne; Bahia; Rio de Janeiro. 



Hyporhamphus tri&uspidatus, GILL, Proc. Ac. Nat. Sci. Phila., 1859, 131, Barbadoes. 



Hemirhamphus fasciaius, POEY, Memorias, 11, 299, 1861, Cuba; not of BLEEKER. 



Hemirhamphw poeyi, GATHER, Cat., vi, 262, 1866; after POEY. 



