[11] FLOUNDERS AND SOLES, 235 
a. Gill openings very small, separate, each reduced to a slight slit below angle of 
opercle ; right ventral beginning at the chin, confluent with the anal; 
pectoral fins wanting or very small; lateral line present, straight; eyes 
small; snout dilated, the dorsal beginning upon it. 
b. Seales present, ctenoid ; caudal fin somewhat confluent with dorsal. 
c. Left ventral rudimentary, with two rays .----..------------ APIONICHTHYS, 39. 
ec. Left ventral well developed, with five rays...-....----------./ A CHIROPSIS, 40. 
bb. Seales none; caudal fin not confluent with dorsal and anal.-GYMNACHIRUS, 41. 
aa. Gill openings of moderate extent, confluent below. 
d. Vertical fins well separated. 
e. Right ventral fin with extended base, confluent with the anal fin; verte- 
bree about 28; body ovate in outline, the depth nearly half the length ; 
pectoral fins rudimentary or wanting; lateral line straight; scales well 
developed, ctenoid, those on the head more or less enlarged, those of the 
blind side of the head with fringes...............---.------ ACHIRUS, 42. 
ee. Right ventral fin with short base, free from the anal; vertebrie 34 to 50; 
body elliptical or elongate, the depth one-third to two-fifths the length ; 
lateral line single* on both sides. 
f. Vertebre 34 to 40; body oblong; pectoral fins usually small, sometimes 
WiekbIN cvOnh ben Obit. S10 Ge ae meen cree a Sey ye a MONOCHIRUS, 43. 
ff. Vertebr 47 to 50; body elongate; pectoral fins subequal, present on 
| CC ARES SIS Sag eye eae arte el a LEO ae a EN Se AAs SP oe Soma, 44. 
dd. Vertical fins fully confluent around the short tail, body oblong; scales very 
small, ctenoid; vertebre, (zebra) 8-+-41—49.............-.-. BRACHIRUS, 45. 
Subfamily VI.—CYNOGLOSSINZ. 
(Soles with the eyes on the left side, not separated by a bony ridge.) 
Body elongate, more or less lanceolate in outline, with the eyes and 
color on the left side; eyes small, very close together, with no distinct 
interorbital ridge between them ; mouth small, twisted toward the blind 
side; teeth little developed, in villiform bands; edge of preopercle 
covered by the scales; gill openings narrow, the gill membranes adnate 
to the shoulder girdle above, joined together and free from the isthmus 
below; pectoral fins wanting (in the adult); ventral fins small, that of 
the blind side often wanting; vertical fins more or less confluent; scales 
ctenoid; lateral line sometimes wanting, sometimes duplicated. 
a. Ventral fin of eyed side only present, free from the anal ; no pectoral fins; no 
lateral lines headawithouttnnoes:2-<- 424228 254 anes nA SYMPHURUS, 46. 
Subfamily I.—HIPPOGLOSSIN 
Genus I.—ATHERESTHES. 
Atheresthes Jordan & Gilbert, Proc. U.S. Nat. Mus., 1880, 51 (stomias). 
TyPE: Platysomatichthys stomias Jordan & Gilbert. 
The single species which constitutes this genust{ is one of the most 


*Two lateral lines on the blind side in the Asiatic genus, Pardachirus. 
t Arrow-shaped canine-teeth are also found in the Asiatic genus Psettodes Bennett, 
a curious group somewhat allied to Atheresthes. In Psettodes, the caudal fin is rounded, 
the dorsal fin begins on the nape, above middle of the cheek, the scales are small and 
etenoid, and there are no gill-rakers. 
