76 ATHERINID^: SILVERSIDES 



(2.2 to 2.5) times in head; second spine longest. Base of slightly fal- 

 cate second dorsal shorter than its height, which is contained 1.5 (1.4 

 to 1.7) times in head. Anal fin somewhat falcate, a little higher than 

 second dorsal; its base slightly shorter than (in paratypes as long as, 

 or a httle longer than) the head. Pectoral pointed, 1.3 (1.2 to 1.4) in 

 head, overlying the anterior one-fourth (to two-fifths) of the length 

 of the depressed ventral fin. 



Some specimens, including the holotype, are very light in color, 

 while others are deep brown ; scales of the back in light specimens, 

 and those of the sides also in dark ones, dark-margined. Lateral band 

 distinct, about as wide as a scale on the tail. Snout and chin more or 

 less deeply pigmented. Colors of the fins varying with that of the 

 body. Peritoneum silvery, mottled with dusky and spotted with black, 

 in light-colored individuals; uniform black in the darkest ones. (A simi- 

 lar wide range of coloration occurs in the series of humboldtianum 

 from Xochimilco.) 



122. Chirostoma chapalae Jordan and Snyder, 1900.-^'- 

 (Plate VIII, Fig. 28) 

 Chirostoma chapal^ Jordan and Snyder, Bull. U. S. Fish Comm., 19, 135, fig. 13. 

 1899 (1900); Jordan and Evermann, Bull U. S. Nat. Mus., 47, pt. 4, 3159, 

 1900; Pellegrin, Bull. Mus. Hist. Nat. Paris, 7, 205, 1901; Meek. Piibl. Field 

 Mus. (Zocl), 3, 115, 1902; 5, 176, fig. 58. 1904; Regan. Biol. Centr.-Amer.. 

 Pisces, 61, 1907. 

 Type-locality. — Laguna de Chapala, near Ocotlan, Mexico. 

 Range. — Lake Chapala, Mexico. 



The following variations are exhibited by a series of twelve speci- 

 mens of C. CHAPAL^^i from La Palma. Depth of body, 5.2 to 6.2 in 

 length to caudal (60 to 78 mm.) ; length of head (including opercular 

 membrane), 4.0 to 4.4; length of snout, 3.4 to 3.8 in head; orbit, 3.3 

 to 3.6 ; mandible, 2.5 to 2.7 ; scales in 48 to 52 transverse series, in 

 13 or 14 longitudinal series above anal origin, in 7 to 9 series between 

 origins of dorsals ; fin rays ; dorsal, IV or V-I, 10 to 12 ; anal, I, 19 to 22. 



123. Chirostoma consocium Jordan and Hubbs, new species, 1919.-^*- 



Chirostoma grandocule Meek, Puhl. Field Mus. (ZooL), 3, 115, 1902 (in part) ; 

 5, 176, 1904 (in part). 

 Chirostoma grandoculis Regan, Biol. Centr.-Amer., Pisces, 61. 1907 (in part) 

 (not Atherinichthys grandoculis Steindachner). 

 Chirostoma consocium Jordan and Hubbs, new species. 



Type-locality. — Lake Chapala, at La Palma, Michoacan, Mexico. 

 Range. — Lake Chapala and its outlet, Rio Grande de Santiago. 



Holotype. — A specimen 77 mm. long to caudal base, from Lake 

 Chapala, at La Palma, Michoacan, Mexico ; collected by Dr. S. E. Meek. 

 May 30-31, 1901; Cat. No. 3672, Field Museum of Natural History; 

 taken with numerous paratypes of smaller size. Other paratypes were 



