THE FISHES OF PORTO RICO. 
15 V) 
Genus 71. DIPLECTBUM Holbrook. The Squirrel-fishes. 
This genus is very close to Prionodes, from which it differs chiefly in the armature of preopercle, 
which is provided in adult with one or two clusters of strong, straight, divergent spines. Smooth area 
on top of head, as in i Serranus, large, extending backward to a line connecting borders of preopercle; 
supraoccipital and parietal crests very short; preorbital broad; maxillary widest before, its tip; profile of 
snout rounded; pectoral unsymmetrically rounded, its upper rays longest; ventral s inserted somewhat 
before axil of pectoral; dorsal spines slender, none of them much elevated; soft dorsal short, rays x, 12; 
anal rays in, 7; caudal lunate. 
Species of small size and bright colors, all American; only one species known from Porto Rico, 
but l>. formosum also doubtless occurs there. 
Halipehca: 
ii. Preopercle with a single center of divergence of the spinules about its angle (in adult as well as in young) . 
b. Gillrakers moderate, about 10 below angle of arch; spines on produced portion of preopercle numerous, 8 to 20 in 
number; outline of spinous dorsal fin somewhat convex, so that the fin is more deeply notched than in Diplectrum 
formosum; jaws equal; vertex naked; opercle black within. 
c. Scales on cheek small and regularly placed, in about 10 rows; 22 scales before dorsal radiate, 111 
Diplectrcm: 
aa. Preopercle with 2 clusters of divergent spines, one at angle, other higher (the 2 fascicles well separated in adult, 
but smaller and coalescent in young). 
d. Head and body marked with many, interrupted blue lines; preorbital broad, more than twice width of maxillary; 
lower half of preopercle with strong, straight spines diverging from two centers; gillrakers short and small, 
x+14; 11 rows of scales on cheek; caudal deeply lunate, upper lobe the longer, sometimes ending in a long 
filament. Color brownish, silvery below; side with 7 or 8 longitudinal deep-blue lines and about as many dark 
crossbars, last bar forming a large black blotch at upper base of caudal; young with 2 broad, dusky longi- 
tudinal stripes, which become interrupted with age; 3 or 4 distinct blue stripeson sides of top of head; 2 across 
preorbital, the lower forked; fins with narrow, wavy bars of blue and pale yellow formosum 
114. Diplectrum radiale (Quoy & Gaimard). A r/uavina. 
Head 2.8; depth 8.8; eye 3.75; snout 3.8; maxillary 2.1; mandible 1.9; interorbital 4.6; preorbital 
9; D. x, 12; A. in, 7; pectoral 1.5; ventral 1.7; caudal 1.35; scales 7-70-18. 
Body elongate, dorsal and ventral outlines nearly alike save fora depression at nape; head pointed, 
a large, smooth round area above, behind eyes; lower jaw barely projecting; teeth chiefly in one row 
on sides of jaws, in small patches in front; maxillary reaching posterior edge of pupil; eye large, 
placed high in head; about 9 rows of regularly placed scales on cheek; preopercle with a strongly 
salient angle composed of radiating spines; opercle with 7 or 8 rows of scales. Dorsal fin continuous, 
slightly notched, spines slender and very sharp; caudal lunate, upper lobe very slightly produced. 
Scales strongly ctenoid. 
Color in spirits: Olive, paler below; many faint vertical dark bars wider than interspaces, plainest 
at middle of sides; 2 faint longitudinal dark bands, first from shoulder to soft dorsal, other from nearly 
same origin to base of caudal, where it forms a faint dark spot; some faint, pale streaks on preorbital and 
cheek. In life, the soft dorsal has blue spots encircled by darker blue rings; caudal barred with similar 
spots; body light-brown above, yellowish below, sides salmon-color, head and fins with red shadings. 
Found on both coasts of tropical America, north to Havana and Guaymas; very common on the 
coast of Brazil and in the ( lulf of California, usually in shallow bays; apparently not common in Porto 
Rico, where one young individual, 5 irfehes in length, was collected at Mayaguez. 
Serranus radialis Quoy & Gaimard, Voyage Uranie, 310, 1824, Rio Janeiro. 
Serranus birittatus Cuvier Valenciennes, Hist. Nat. Poiss., II, 241, 1828, Martinique. 
Ceniropristes ayresi Steindacliner, Ichth. Notizen, VII, 1, pi. 1, fig. 1, 1868, Santos, Brazil. 
Diplectrum radiale, Jordan & Evermann, 1. c„ 1204, 1896. 
Genus 72. PRIONODES Jenyns. Serranos. 
Body oblong, moderately compressed, covered with moderate-sized ctenoid scales. Lateral line 
normal in direction, not running close to back. Cranium above with a very large convex smooth area, 
which is longer than the low supraorbital crest; supraoccipital and parietal crests short, extending to 
a line connecting borders of preopercle; posterior outline of cranium nearly vertical in profile; mouth 
large, maxillary' not scaly and without supplemental bone; canines small, lateral; no depressible teeth 
in jaws; teeth always present on vomer and palatines. Gillrakers usually few. Branchiostegals 7. 
Dorsal with 10 rather slender spines either subequal or one of them much produced, the tin not 
