THE FISHES OF PORTO RICO. 
79 
In alcohol the general color is grayish-black, yellowish below, the tawny-ochraceous or yellow 
becoming darker, almost black, and the white spots on body becoming yellowish. 
This species seems to be related to L. obscuratus (Poey), but differs markedly from it in color. 
Only the type (No. 49358, U. S. N. M. ), a specimen about 15 inches long, was obtained. This was 
collected at Mayaguez, January 20, 1899. 
Lycodontis jordani Evermann & Marsh, Rept. U. S. F. C. 1899 (Dec. 19) , 352, Mayaguez, Porto Rico. 
Genus 18. ECHIDNA Forster. 
This well-marked genus is distinguished from the other Morays by the blunt teeth. It contains 
12 or 15 species, most of them belonging to the Western Pacific and representing the highest degree of 
specialization among the morays, as Uropterygius represents the extreme of degradation. The name 
Echidna was suggested for this group of eels long before its application by Cuvier to a genus of Austra- 
lian monotremes. Only one species known from Porto Rico. 
23. Echidna catenata (Bloch). Morena. 
Head 3.7 in trunk; eye 2 in snout, which is 6 in head; cleft of mouth 3 in head; trunk a little longer 
than tail; teeth somewhat molar-like, not very blunt, chiefly uniserial, but reduced in size and biserial 
in rear of upper jaw; a median series on vomer. 
Color in spirits: Ground-color pale-yellow, with some 30 heavy dark-brown transverse bars, some 
oblique, some branched, some connected, forming heavy reticulations; on ventral portion of trunk 
these bars are broken into definite roundish spots, these elongate in front of anal, forming a single 
median series; intermediate pale area of ground-color everywhere marked with dark-brown in spots 
of all sizes from punctulations to the size of pupil or larger; markings of body extend upon fins. 
West Indies, Bermuda to Surinam, generally common. A very handsome eel. Mr. Gray obtained 
3 fine specimens at San Geronimo; our collection contains one, of 6.5 inches, from Arroyo. 
Murxna seu conger brasttiensis Seba, Thesaurus, II, 72, pi. 69, figs. 4 and 5, 1738, Brazil. 
Gymnothorax catenatus Bloch, Ausl. Fische, XII, 74, pi. 415, fig. 1, 1795, Coromandel, an error; Stahl, 1. c., 166, 1883. 
Murscnophis catenula LacOpede, Hist. Nat. Poiss., V, 628 and 641, 1803, Palmerston Island; after Bloch. 
Echidna flavofasciata Poey, Repertorio, II, 264, 1868, Cuba. 
Echidna fuscomaculata Poey, Repertory, II, 263, 1868, Cuba. 
Echidna catenata , Poey, Fauna Puerto-Riquena, 345, 1881; Jordan & Evermann, 1. e., 403, 1896. 
Family XV. ELOPIDtE. The Tarpons. 
Body elongate, more or less compressed, covered with silvery, cycloid scales; head naked. Mouth 
broad, terminal, the lower jaw prominent. Premaxillaries not protractile, short, the maxillaries 
forming lateral margins of upper jaw; maxillary composed of about three pieces, extending backward 
beyond eye; an elongate bony plate between the branches of lower jaw (analogous to gular plate in 
Amici) ; bands of villiform teeth in both jaws and on vomer, palatines, pterygoids, tongue, and base 
of skull; no large teeth. Eye large, with an adipose eyelid. Opercular bones thin, with expanded 
membranaceous borders; a scaly occipital collar. Gill-membranes entirely separate, free from isth- 
mus. Branchiostegals numerous (29 to 35). Gill rakers long and slender. Pseudo branchiae present 
or absent. Belly not keeled nor serrated, rather broad and covered with ordinary scales. Lateral 
line present. Dorsal fin inserted over or slightly behind ventrals; caudal fin forked; no adipose fin; 
dorsal and anal depressible into a sheath of scales; pectorals and ventrals each with a long accessory 
scale. Parietal bones meeting along top of head. Pyloric cseca numerous. 
Genera three, species about five, forming two well-marked subfamilies, both widely distributed 
in the tropical seas. Not much valued as food, the flesh being dry and bony. 
Megalopinve: 
a. Pseudobranchiae none; body oblong, covered with large scales; anal fin larger than dorsal; last ray of dorsal pro- 
duced in a long filament. 
b. Dorsal fin inserted notably behind insertion of ventrals Tarpon, 19 
Elopin;e: 
aa. Pseudobranchise large; body elongate, covered with small scales; anal fin smaller than dorsal; last ray of dorsal 
not produced in a filament Elops, 20 
