ElGENMANN : COLLECTIONS OF FlSHES FROM PARAGUAY. 121 



27. Loriearia parva Boulenger. 



Ten specimens, Corumba (339, 349, 300, 301). Four from Laguna 

 Pasito, at Ascuncion (461). 



28. Loricaria labialis Boulenger (Plate XXXVI I., Figs. 3-4). 

 Four specimens from Corumba (319). 



29. Otocinclus viitatus Regan (Plate XXXVIII., Fig. 1). 



One specimen (part of 304), Corumba; two specimens (446), 

 tributary of the Pilcomayo. 



Description of the Corumba Specimen. — Body rounded in front, 

 compressed toward tail ; its greatest width less than depth ; profile 

 straight, less steep than in affinis. Occipital process terminating in 

 an elevated, triangular process; ventral and dorsal profiles similar; 

 sides of head vertical, eyes distinctly lateral. Interorbital convex ; 

 a groove running from snout to nares. All the bones of the head 

 hispid ; head nearly covered with spines ; spines minute on occipital, 

 strongest on border of snout. Orbit 2 in the snout, 4 in the head, 2 

 in the interorbital. Snout pointed. Lower surface of the head naked 

 except a triangular space below the eye. Lateral plates hispid. 

 Distance of dorsal fin from tip of snout 2^ in the length. Dorsal 

 spine as long as head. Caudal forked. Pectoral extending little 

 beyond origin of ventrals. Ventrals reaching nearly to anal. Color 

 light brown above with a broad dusky bar extending from snout to 

 end of caudal ; tips of caudal dark ; black bands extending from end 

 of dark band on middle caudal rays first backward, then forward, form- 

 ing with the median band a T-shaped figure. 



Head 3^ ; D.I, 6 ; A. 6 ; V. 6 ; P.I, 6 ; C. 16 ; Lat. I.23. 



The two from Pilcomayo are very beautiful, well-preserved speci- 

 mens, which are slightly longer than the Corumba specimen, being 

 34 mm. and 25 mm. long. They agree with it in all except the color, 

 which is faded. Traces are visible of the dusky lateral band and 

 markings on the caudal fin. The specimens have the appearance of 

 having been preserved in some corrosive sublimate preparation, or 

 having lived in a cave ; one of them has D.I, 7. 



Key to the Species of Otocinclus. 



a. Sides with a longitudinal band. 



b. Middle caudal rays black. D.T, 6 or 7. 



c. Tips of caudal dark ; black bands extending from end of the dark band 

 on middle caudal rays first backward and then forward, forming with 

 the median band a T-shaped figure ; a well-defined band from tip of 

 snout to caudal, widest at the caudal peduncle, blackest on caudal. 



