MUSEUM OF COMPARATIVE ZOOLOGY. 89 
Some of the following species have a special interest on account of their 
locality. The majority are from small streams or springs flowing into the 
Lago del Muerte or the Lago de Parras, in the southwestern part of the State 
of Coahuila, Mexico. These lakes or lagoons are said to be completely isolated. 
They are marked so on the latest maps of this portion of the country, The list 
is compiled from a collection made for the Museum by Dr, Edward Palmer. 
Noturus flavus Rar. 
San Antonio, Texas. 
Ichthyobus tumidus GIRARD. 
D.3+26; 4.84-8 ) V. 11; P. 16 ; L. lat. 37; L. trans. 74145. 
San Pedro, on the Nazas River, flowing into the Lago del Muerte from the 
west. 
Catostomus nebuliferus sp. nov. 
D.3--9; A. 2-]-8; V.1+8 (-9); P. 15; L. lat. 90; L. trans. 14-1- 1 ๆ - 14. 
Length of head or height of body one fifth of the total, exclusive of the 
caudal. Body stout, little compressed. Head moderate, nearly as broad as 
high, length in front of the eye almost twice the diameter of the orbit. Eye 
small, Mouth small; lips with a considerable free margin. Anterior spine 
of the dorsal midway between the muzzle and the caudal; a vertical from 
the middle of the base of the fin reaches the insertion of the ventrals ; the 
latter extend to a vertical from the posterior extremity of the free portion. 
Jaudal deeply notehed. . Anterior rays of dorsal and ventral longer. 
Reddish brown to brown, clouded and blotehed with darker.  Darker 
along the lateral line. Belly light colored, uniform. Lower half of the pre- 
operele silvery white. The line of demarcation between the dark color of 
the upper portion of the head and the light of the face and throat is very 
distinct. Allied to O. guzmamensis Girard ; differing in the radial formule 
and, somewhat, in coloration. It differs from C. griseus Girard in radial for- 
mule, squamation, and colors, 
Nazas River. 
Hybognathus (Dionda) punctifer sp. nov. 
D. 2-4-8; A. 2--8; V. 8; P. 16; L. lat. 40; L. trans. 6 ๆ - 1-]- 3. 
Teeth 4-4, compressed, clawed. 
Length of head or height of body equal to one fourth of the total, without 
caudal. Body but slightly compressed, outline from forehead to dorsal curving 
regularly. Head moderately broad ; snout rounded, little, if any, longer from 
the eye than the diameter of the orbit. Eye medium. Mouth small; maxil- 
