1907.] NEW LORICARIID FISHES. 79^ 



Otocinclus paulinus, sp. n. 



Depth of body 5 in the length, length of head 24-. Diameter 

 of eye 7| in the length of head, interoi-bital width 2f , length of 

 snout 2|. Occipital region evenly convex, without crests. Scutes 

 spinulose, not carinate, 22 in a longitudinal series. Lower surface 

 of head with a naked area in front of the clavicles ; abdomen 

 posteriorly with numerous small plates, anteriorly naked except 



Text-fiff. 208. 





Otocinclus ^a^dinus (X 2). 



for a series of plates on each side. Dorsal I 7 ; origin above the 

 base of ventral ; no adipose fin. Anal I 4. Pectoral spine extend- 

 ing beyond middle of ventral. Caudal emarginate. Caudal 

 peduncle 3 times as long as deep. Caudal blackish, except the 

 postei^ior half of the upper lobe, which is pale with dark spots \^ 

 other fins pale with series of dark spots. 



Hah. Rio Piracicaba, San Paulo, Brazil. 



A single specimen, 35 mm. in total length, received from 

 Dr. R. von Ihering. 



Arges heterodon, sp. n. (Plate XLIX. fig. 2.) 



Length of head 4 in the length of the fish. Nasal flap pro- 

 duced into a short barbel, Interocular width equal to the distance 

 from eye to posterior nostril and 3 in the length of head. Width 

 of mouth Tj the length of head ; outer series of teeth in the prse- 

 maxillaries unicuspid, more or less compressed, expanded and 

 truncated ; mandibulary teeth acutely bicuspid ; barbel just 

 reaching the gill-opening. Dorsal I 6 ; first ray produced, longer 

 than the head ; adipose fin elongate, strongly developed, without 

 trace of a spine. Pectoral spine probably produced and extending 

 beyond the middle of ventral (broken off on each side) ; ventrals 

 longer than the head, originating a little in advance of the origin 

 of dorsal, extending nearly to the vent, which is situated at more 

 than |- of the distance from the base of the ventrals to the origin 

 of the anal. Anal I 6. Distance from tip of snout to origin of 

 dorsal 2| in the length of the fish, from base of last anal ray to 

 that of the caudal 5|, Greyish, spotted and marbled with blackish ;. 

 vertical fins with series of blackish spots. 



Hah. Jimenez, Western Colombia. 



