152 OSTAEIOPHYSI. 



than e3T, the diameter of which is 4i to 5 in the length of head ; intcrorhital width 2= to 3 in the length 

 of head. 10 gill-rakers on the lower part of the anterior arch. G5 to 76 scales in a longitudinal series, 

 13 to 16 in a transverse scries from dorsal fin to lateral line, S to 11 Ijctween lateral line and base of 

 ventral fin. Dorsal 0, with 7 branched rays ; origin equidistant from tip of snout and base of caudal or 

 slightly nearer the latter ; free edge straight ; longest ray | the length of head. Anal 8, witli 6 branched 

 rays. Pectoral i| the length of head, not reaching the ventrals, which are inserted below the origin of 

 the dorsal. Traces of a dark lateral band ending in a caudal spot. 



Hal. Mexico, Rio Lerma and upper tributaties of the Ttio Panuco i. 



Here described from several specimens, 90 to 120 mm. in total length, from Aguas 

 C'alientes [Jordan), Salamanca [Woohnan), and San Juan del Rio [Meek). 



This species has a shorter head and larger eye than A. tincella, but is especially 

 distinguished by the fewer scales between the lateral line and the ventral fin. 



3. Algansea stigmatura, sp. n. (Tab. XXV. fig. 2.) 



Depth of body 4 to 4| in the length, length of head 3.5 to 4. Snout as long as eye, the diameter of which is 

 4 in the length of head ; intcrorhital width 2| to 3 in the length of head. 13 or 14 gill-rakers on the 

 lower part of the anterior arch. 60 to 60 scales in a longitudinal series, 13 to 15 in a transverse series 

 from origin of dorsal to lateral line, 7 or S between lateral line and base of ventral fin. Dorsal 9, with 

 7 branched rays ; origin equidistant from tip of snout and base of caudal ; free edge straight ; longest, 

 ray | the length of head. Anal 8. Pectoral s the length of head, not reaching the ventrals, which are 

 inserted nearly below the origin of dorsal. Silvery ; a dark caudal spot. 



llah. Mesico, Rio Grande de Santiago. 



Four specimens, 55 to 75 mm. in total length, collected by Dr. A. C. Buller. 



4. Algansea dugesi. 



Ahiansea dugnsi, Bean, Proc. U.S. Nat. Mus. 1892, p. 283, t. 44. fig. 1 ' ; Jord. & Everm. Bull, 

 U.S. Nat. Mus. xlvii. 189G, p. 212', and 1900, fig. 98 ' ; Meek, Publ. Columbian Mus., 

 Zool. V. 1904, p. 45, fig. 8'. 



Algansea lucustris, Steind. Deukschr. Ak. Wien, Ixii. 1895, p. 526, t. 3. fig. 1 '; Meek, t. c. p. 47 °. 



Algansea tarascorum, Steind. t. c. p. 527, t. 3. fig. 2\ 



? Algansea rubescens, Meek, t. c. p. 46, fig. 9 '. 



Depth of body nearly equal to the length of head, which is Sj to 4 in the length of the fish. Snout longer 

 than eye, the diameter of which is 4.] to in the length of head ; intcrorhital width 3 in the length of 

 head. 15 to 17 gill-rakers on the lower part of the anterior arch. 76 to 86 scales in a longitudinal 

 series, 18 to 21 between dorsal fin and lateral line, 12 to 15 between lateral line and root of ventral. 

 Dorsal 9, with 7 branched rays ; origin ecjuidistant from tip of snout and base of caudal or a little nearer 

 the latter; free edge straight; longest ray j to j the length of head. Anal 8, with 6 branched rays. 

 Pectoral jj- to i| the length of head, not reaching the ventrals, which arc inserted nearly below the origin 

 of dorsal. Silvery, hack darker ; young with a dark spot at the base of caudal. 



Ilab. Me.xico, Rio Lerma System : 



Lake Yuriria in Guanajuato ^ ; Lake Chapala in Jalisco ^ ; Lake Patzcuaro in 

 Michoacan * •'^ ". 



Here described from three specimens, 100 to 200 mm. in total length, from 



