Hugh M. Smith

Sikukia stejnegeri, a New Genus and Species of Freshwater Cyprinoid Fishes from Siam

DIA GNOSIS.-Form moderately elongate, strongly compressed; head very small; snout entire, very short, blunt, and abruptly decurved; rostral fold covering base of upper lip; mouth small, terminal; lips thin, continuous around corners of mouth, lower lip firmly adherent to sharpedged lower jaw; postlabial groove interrupted in middle of lower jaw; a small but distinct symphysial tubercle on lower jaw; nostrils placed high on snout, on level with upper border of eye and nearer to eye than to tip of snout; barbels absent; eye large, with narrow annular adipose lid; scales of moderate size; lateral line complete and running in middle of caudal peduncle; a scaly sheath at base of dorsal and anal fins; gillmembranes united to isthmus; gill-rakers rudimentary. Dorsal short, with 8 branched rays, last simple ray strongly ossified and denticulated posteriorly; dorsal origin over ventral base, its termination well in advance of anal; caudal forked; anal branched rays 6, last simple ray weakly ossified. Remarks.-In the short, blunt snout, large eye, adipose eyelid, absence of barbels, and denticulated dorsal ray, this genus resembles Amblyrhynchichthys in which, however, the mouth is inferior and larger, the upper lip is partly covered by a broad, triangular fold, and the nostrils are at the end of the snout and partly inferior. Resemblance to Albulichthys is seen in the terminal mouth, adipose eyelid, serrated last simple dorsal ray, and absence of barbels, but in that genus the mouth is much larger, the maxillary reaches a vertical from the anterior border of the eye, the snout is long and gently arched, the basal half of the caudal is covered with scales, and the gill-rakers are long and numerous. (Sikukia, from the Sikuk River, Siam.)