260 silurid^;. 



15. Loricaria acipenserina. 

 Hemiodon acipenserinus, Kner, Loricar. p. 28. taf. 7. fig. 2. 



Snout long and narrow, terminating in a spiny knob. Eye small, 

 its diameter being one-half of the width of the interorbital space, 

 which is concave ; orbit with a triangular notch behind. Teeth ab- 

 sent in the upper jaw, minute and rudimentary in the lower. The 

 lower side of the head naked. Scutes of the head and nape rough 

 and keeled. Anterior part of the thorax naked ; abdomen with five 

 transverse series of large scutes, three in each series. The origin 

 of the dorsal fin is somewhat behind the vertical from the base of the 

 first ventral ray. The upper caudal ray prolonged. Upper parts 

 and fins with black spots. (Kner.) 



Rio Guapore, Matogrosso. 



(y. Species the dentition of which is not, or imperfectly known.) 



16. Loricaria lima. 



Kner, Loricar. p. 25. taf. 6. fig. 1. 



Snout broad, the head being not much longer than broad; the 

 diameter of the eye is one-half of the width of the interorbital space ; 

 orbit with a deep notch behind. Mandibles with rather long teeth*. 

 Sides of the head with loijg bristles ; scutes of the nape bicarinate. 

 L. lat. 29-30. Thorax and abdomen with small, irregular scutelhe. 

 The origin of the dorsal fin is somewhat behind that of the ventrals. 

 (Kner.) 



Brazil. 



17. Loricaria brunnea. 

 Hancock. Zool. Journ. iv. p. 247. 



Teeth? 



The scutes on the lower side of the trunk are not divided, reaching 

 across from one side to the other; mouth without barbels. (Hanc.) 



Orinoco. 



100. ACESTRA. 

 Acestra, Kner, Denkschr. Acad. Wiss. Wien, 1853, vi. Loricar. p. 11. 

 One short dorsal fin, opposite to the anal ; anal fin short ; the outer 

 ray of each fin somewhat thickened, flexible. Snout very long and 

 narrow ; mouth situated at the lower side of the snout, remote from 

 its extremity, transverse, with a broadish posterior labial fold. Teeth 

 in both jaws, small, bent, with a dilated, notched apex, in a single 

 series ; no teeth on the palate. Head and body completely cuirassed ; 

 tail depressed, long ; eye rather small. Praeoperculum immoveable ; 

 gill-opening very narrow. Formula of the fins : D. 1/6. A. 4-6. 

 P ±. Y.-L 



6-6 4-5' 



Fresh waters of Brazil and Surinam. 



* In consequence of the bad condition of the single example known, Prof. 

 Kner was unable to determine the dentition in the upper jaw. 



