Paiexostoma, Cliimanliichthys and Exostoma. 183 



A. Caudal fin truncate or very sliglitly emar^dnato. 



Origin of dorsal posterior to the extremity of [Regan. 



pectoral ; anal with I 5 rays \. E. Vinciguerrcc, 



Origin of dor.sal above posterior ^ of pectoral; [Day. 



anal with I 7 rays 2. E. Andersonii, 



B. Caudal fin forked or ratlier deeply emarginate. fBlvth 



Pectoral with 10 branched rays Z. E. Berdmorii, ' 



Pectoral with 12 branched ravs i. E. labiatuin, 



[MacClell. 



Parexostoma. 



1. Parexostoma Stoliczkce. 



Exostoma StoUczk.-e, Day, Proc. Zool. Soc. 1876, p. 782 ; Second Yarkaud 

 Mission, Ichthyologv, p. 1, pi. i. fig. 1 (1878); Fishes of India, 

 p. 502, pi. cxvi'i. fig."3 (1878). 



Exostoma Oschanini, Herzenstein, Bull. Ac. St. Petersburg, xxxiii. 

 1800, p. 120. 



Hah. Eastern Turkestan. 



2. Parexostoma maculatam, .sp. n. 



Depth of body about G in the length, lengtli of head 

 nearly 4. Head as broad as long. Eyes sniaU. Snout as 

 long as postorbital part of head and 1| the interocular width. 

 Nasal barbel extending to eye, maxillary barbel to base of 

 pectoral, outer niandibulary barbel to gill-opening. Dorsal I 6, 

 commencing sliglitly in advance of the extremity of pectoral ; 

 adipose tin as long as or longer than its distance from the 

 dorsal. Anal 1 5. Pectoral with 11 branched rays, ex- 

 tending \—i of the distance from its base to the base of ventral. 

 Ventral with 5 branched rays. Caudal truncate. Caudal 

 peduncle twice as long as deep. Olivaceous, with numerous 

 irregular dark spots ; caudal with a white posterior margin. 



Two specimens, 210 and 255 mm. in total lengthy from 

 Lhasa, Tibet, collected by Capt. H. J. Walton. 



Chimarrhichthys. 



Chimarrichthys, Sauvage, Rev. et Mag. Zool. xxv. 1874, p. 332, 



1. Chimarrhichthys Davidi. 



Chimarrichthys Davidi, Sauvage, Rev. et Mag. Zool. xxv. 1874, p. 333. 

 Exostoma Davidi, Giiuth. in i'ratt, Snows of Thibet, Appendix, p. 245 

 (1692). 



Jlab. Eastern Tibet. 



13* 



