THE FISHES OF PORTO RICO. 
99 
ff. Eye moderate, 2 to 3.25 in postorbital part of head. 
g. Caudal fin forked; caudal keel sharp, broad, and conspicuous; top of head flat, striated, without median groove; 
case of upper jaw much depressed; maxillary entirely hidden by preorbital; teeth very small; ventral fin mid- 
way between eye and caudal; scales not very small. D. I, 13; A. i, 18 ardeola, 49 
gg. Caudal fin unequally lunate, the emargination not deep, the lower rays moderately produced; scales very small; 
sides with a silvery lateral stripe; caudal keel not very conspicuous, not black; top of head with median groove; 
maxillary not entirely concealed by preorbital; ventral inserted midway between preopercle and base of 
caudal. Species of moderate size, with the scales and bones more or less green. 
h. Eye moderate, 2.5 in postorbital part of head; pectorals not black posteriorly. D. I, 15; A. I, 17; lateral line 300; a 
dark bar on opercle marinus 
hh. Eye small, 3.25 in postorbital part of head. D. 13 or 14; A. 15 or 16; pectoral pale almeida 
ee. Dorsal and anal fins long, each of 17 to 25 rays, last rays of dorsal fin more or less elevated in the young, becoming 
lower in adult; caudal keel rather strong, black; one or more folds of skin across edge of preopercle; caudal 
fin deeply emarginate or unequally forked. Ventrals inserted midway between base of caudal and middle of 
eye. Species of large size, with scales and bones green; no distinct lateral stripe. 
i. Beak short and very strong, its length 1.5 to 1.33 times length of rest of head; body comparatively robust, depth more 
than one-fifth length of head. 
j. Dorsal fin long, its rays 1,21 to 1,24; anal rays 1 , 22 to 1,24; insertion of dorsal almost opposite that of anal; snout 
longer, 1.66 to 1.83 length of rest of head; lateral line about 350 raphidoma, 50 
jj. Allied to T. raphidoma, but insufficiently characterized galealus 
ii. Beak strong, but more elongate, about twice length of rest of head; dorsal beginning behind front of anal; greatest 
depth of body about two-thirds length of pectoral. D. 1 , 23; A. 1 , 21; lateral line 380; no lateral stripe acus 
aa. Mouth not closing completely, upper jaw arched at base; lobes of dorsal and anal low, the last rays elevated; eye 
very large, 2.1 in head; scales small, green. D. 24; A. 22; a bluish lateral band caribbxus 
48. Tylosurus timucu (Walbaum). “ Agujon.” 
Head 2.75; depth 7; eye moderate 2.33 to 2. 75 in postorbital part of head; scales small, 225, about 
150 before dorsal: D. 15; A. 17. Body very slender, subterete; caudal peduncle not keeled; ventrals 
inserted nearer cheeks than base of caudal. No distinct temporal notch; maxillary not entirely 
concealed. Scales and bones not green. Greenish; a silvery-bluish lateral band, widened below 
dorsal; no scapular spot. Length 1J feet. Florida Keys to Brazil; not rare. 
Found by us at San Juan. Palo Seco, and Hucares, and doubtless occurring everywhere about the 
island. By the natives all the species of Tylosurus are known as “agujon.” 
Timucu or Peixe agulha, Marcgrave, Pise. Brasil., 168, 1648, Brazil. 
Esox timucu Walbaum, Artedi Piscium, III, 295, 1792, Brazil; after Marcgrave. 
Betone subtruncata Poey, Memorias, II, 295, 1861, Havana. 
Belonc depressa, Poey, Memorias, II, 296, 1861, Havana. 
Tylosurus sagitta Jordan & Gilbert, Proc. U. S. N. M. 1884, 25, Key West. 
Tylosurus timucu, Jordan & Evermann, 1. c., 711, 1896. 
49. Tylosurus ardeola (Cuvier & Valenciennes) . “ Agujon.” 
Head 3.75; depth 8 in head; eye 7; lower jaw from eye 4 in eye (upper jaw broken in our 
specimen); interorbital equal to eye; I). 13; A. 17. Body very slender; head broad and flat, much 
broader than in a specimen of T. timucu of same size; upper jaw depressed; preorbital completely cov- 
ering maxillary; teeth small and weak; no fold of skin on opercle; caudal peduncle depressed, with 
a strong sharp keel; scales moderate, about 150 before dorsal; origin of dorsal decidedly behind that 
of anal; caudal unequally lunate, lower lobe the longer; ventrals midway between eye and caudal. 
Our collection contains a specimen of Tylosurus, 13 inches long, obtained at Isabel Segunda, which 
we are not able to identify with certainty. It is much emaciated and starved in appearance, with 
very short jaws, which have probably been broken. It seems to agree with the brief description 
given by Cuvier & Valenciennes of their Belone ardeola and also of their B. cigonella, the type of which 
came from Porto Rico. 
Belone ardeola Cuvier & Valenciennes, Hist. Nat. Poiss., XVIII, 425, 1846, Martinique. 
Belone cigonella Cuv. & Val., Hist. Nat. Poiss.', XVIII, 436, 1846, Porto Rico; Poey, Fauna Puerto-Riquena, 337, 1881. 
Tylosurus ardeola, Jordan & Evermann, 1. c., 713, 1896. 
50. Tylosurus raphidoma (Ranzani). “Agujon”; Hound-fish. 
D. 21 to 24; A. 22 to 24; scales 350. Caudal keel rather strong, black; one or more folds of skin 
across edge of preopercle. Body robust, little compressed, its greatest breadth a little more than two- 
thirds greatest depth; caudal peduncle slightly depressed, a little broader than deep, with a slight 
black dermal keel. Head broad, interorbital space nearly two-thirds length of postorbital part of 
