218 MEMOIRS OF THE CARNEGIE MUSEUM. 



Paracheilognathus rhombeus Bleeker, Atl. lehtln'ol. Cypr., 1863, p. 33. 



Achilognathus rhombeus Glinther, Cat. Fish., VII, 1868, p. 279; Nagasaki, from one of Sclilegel's types; 



Ishikawa, Prel. Cat., 1897, p. 12; Tokyo, Lake Biwa, Yamashiro. 

 Paracheilognathus rhombea Jordan and Fowler, Proc. U. S. N. Mus., Vol. XXVI, 1903, p. 815, Lake Biwa, 



Yodo River, Chikugo River, Funayado; Lake Yogo, Tanaka, Ann. Zool. Jap., VII, Part. 1, 1908, 



p. 2; Lake Biwa, at Katata and Iba. 

 Acheilognathus rhomheuin Jordan & Snyder, Proc. U. S. N. M., XXIII, 1901, p. 343; Lake Biwa. 

 Achilognathus steenackeri Sauvage, Bull. Soc. Philom., Paris, 1883, p. 3; Lake Biwa. 



Apparently the genus Paracheilognathus Bleeker, of which this species is type, 

 characterized by the plicate teeth and the long dorsal, cannot be separated from 

 Acheilognathus. The species of this genus, very numerous in Japan and China, are 

 much alike in appearance and have been the object of much confusion. 



This species is here described from numerous specimens from Lake Biwa and 

 Chikugo, the longest 11.5 cm. in total length. These are in part those of Jordan and 

 Fowler (Proc. U. S. Nat. Mus. XXVI, p. 815). 



Depth 2.5 to 2.12 in body-length; D. Ill, 12 (11 to 14); A. II, 10 (9 or 10); 

 scales in lateral line thirty-five to thirty-eight, in transverse series between insertion 

 of vertical fins 6/5 or /6; pharyngeal teeth 5-5. 



Head 4 in body-length; snout 3.56 in head; mouth horizontal, tip of pre- 

 maxillaries level with lower edge of orbit; profile of snout arched at nostrils, that 

 of occiput strongly depressed in adults; eye equal to snout or somewhat less; barbels 

 very short, at most, eight times in eye; gill-rakers 4 4-11 on first arch, equal in length 

 to barbels; pharyngeal teeth folded or plicate on the lower lateral face of each in a 

 transverse direction, not truly serrate, with narrow grinding surface and hooked 

 tip; depth of caudal peduncle slightly more than half the length of head, its length 

 1.25 in head. 



Dorsal inserted midway between snout and base of caudal, its base 1.12 times 

 length of head, its height nearly equal to head; outline of fin rounded, first rays 

 not extending beyond base of last when supine ; anal inserted under sixth branched 

 dorsal ray, its base 1.5 in that of the dorsal, its height 1.5 in head, margin rounded, 

 first rays not extending beyond base of last; pectorals and ventrals 1.5 in head. 



Body dark above, especially on line of back; a blue-black strij^e as wide as pupil 

 arising abruptly at fourth scale from last in lateral line and extending forward to 

 below first branched rays of dorsal; a blue-black spot just behind and above angle 

 of opercle nearly as large as eye. Dorsal fin-rays with a white spot on each, half- 

 way to tip, the membranes marked with a corresponding blue-black blotch, just 

 behind white parts of rays; often a second row of white spots on rays distal to the 

 others and separated by darker spaces, giving the appearance of two fine stripes; 



