28 



ZOOLOGY. 



51. CATOSTOMUS OCCIDENTAL-IS, Ayres. 



General Report upon Fishes. 



Eye and mouth of medium size ; labial papillae small aud rather inconspicuous. Isthmus 



very broad. Dorsal fin longer than high. Anterior margin of ventrals corresponding to the 



middle of the dorsal fin. Posterior extremity of anal reaching the rudimentary rays upon the 



inferior lobe of the caudal ; latter moderately forked. Upper regions of a greyish lead tint ; 



beneath, of a soiled yellow or white. 



A true " Sucker." 



List of specimens. 



52. CATOSTOMUS LABIATUS, Ayres. 

 General Report upon Fishes. 



Eye small ; mouth of medium size ; labial papilla? conspicuously developed. Dorsal fin 

 higher than long. Pectoral fins quite elongated and well developed. Insertion of ventrals 

 situated opposite the posterior third of the base of the dorsal. The scales are large. Upper 

 regions black ; lower half of sides black, clouded upon a yellow ground, whilst the belly and 

 inferior surface of the head are yellow — almost unicolor. 



Another true " Sucker," and so called by fishermen. 



List of specimens. 



53. ORTHODON M1CEOLEPIDOTUS, Grd. 

 Plate LIII, figs. 1-4. — General Report upon Fishes. 



Head moderate, its upper surface flattened and declivous towards the snout, which is obtusely 

 wedge shaped. Mouth moderate, broad ; posterior extremity of maxillary extending to a ver- 

 tical line intersecting the nostril. Isthmus very narrow. The anterior margin of the dorsal is 

 placed somewhat in advance of the insertion of the ventrals. Peduncle of tail slender. Ven- 

 trals broad. Greyish brown above, whitish or yellowish beneath. 



Has no vernacular name, so far as we have heard. 



