2774 Bulletin 4.7, United States National Museum. 



of its sides. Occipital process sub triangular, not quite as long as broad 

 at base, with a strong median keel, its sides slightly curved. A short 

 distance in front of the beginning of the keel is the end of the very nar- 

 row groove-like fontanel, which is somewhat widened anteriorly, finally 

 merging into the broad, flat, smooth interorbital area, the boundaries of 

 which are not well denned; shields of head unusually smooth, all finely 

 and very sparsely granular, the granules not forming distinct lines. Some 

 specimens (probably females) about as smooth as in the subgenus Gale- 

 ichthys. Gill membranes forming a rather broad fold across isthmus. 

 Dorsal spine long, usually, but not always, shorter than the pectoral 

 spine, about If in head; axillary pore absent; humeral process rather 

 broadly triangular, not much produced backward, less than | length 

 of pectoral spine, its surface not granular, covered with skin; adipose 

 fin length of anal, its posterior margin little free; upper lobe of 

 caudal the longer and somewhat falcate, about as long as head; ventrals 

 long, about reaching anal in females, rather shorter in males ; vent much 

 nearer base of ventrals than anal. Color olive green, with bluish luster, 

 white below; upper fins dusky olivaceous; caudal yellowish dusky at 

 tip ; anal yellowish with a median dusky shade ; ventrals yellowish, the 

 basal half of upper side abruptly black; pectorals similarly colored, the 

 black area rather smaller; maxillary barbel blackish; other barbels pale. 

 Length 12 to 18 inches. Coast of Sinaloa; very common; by far the most 

 abundant species at Mazatlan; not recorded from localities farther south. 



Arius assimilis, JORDAN & GILBERT, Bull. TJ. S. Fish Comm., n, 1882, 47; not of GUNTHER. 

 Galeichthys gilberti, JORDAN & WILLIAMS, Kept. Fishes Sinaloa, in Proc. Gal. Ac. Sci. 1895, 

 395, pi. 26, Mazatlan. (Type, No. 29213. Coll. Chas. H. Gilbert.) 



188. GALEICHTHYS JORDANI (Eigenmann & Eigenmann). 



Head 3-f to 3f ; depth 5| to 5. D. I, 7; A. 18; eye large, If ri snout, 

 5^ in head, 2 in the interorbital, 2f to 3 in the interocular. The specimens 

 agree very closely with the description of assimilis by Jordan & Gilbert 

 (gilberti of the present paper). They differ in the width of the mouth 

 and in having a pectoral pore. Rather robust, the width little less than 

 the depth ; caudal peduncle compressed. Head heavy, little broader than 

 high, its height 1| in its length, its width If to 1, width at the angle of 

 the mouth 2 to 2f; interorbital area flat and smooth; posterior portion 

 of the head finely and sparsely granular; opercle and humeral process 

 smooth; occipital process about as long as broad, unusually sharply 

 keeled; fontanel extending to above the posterior part of the orbit, con- 

 tinuing as a deep groove to the base of the occipital process; maxillary 

 barbels extending to the pectoral pore, postmentals at least to the gill 

 opening, mental about f as long as the postmental barbels; snout blunt, 

 decurved; upper jaw a little produced; teeth all villiform, those on the 

 vouier forming 2 small, separate, ovate patches, which are contiguous to 

 the twice or thrice as large palatine patches ; gill membranes forming a 

 fold across the isthmus; gillrakers 6 -f- 9 ; pectoral pore large; vertical 

 series of pores present; distance of dorsal spine from tip of snout 2* to 2 

 in the length ; the spine of the dorsal and pectoral fins granular on the 



