TOO. ACESTRA. 261 



1. Acestra acus. 



? Loricaria scolopacina, FUippi, liec. et May. ZuuL 1853, p. 166. 

 Acestra acus, Kner, Loricar. p. 30. taf. 8. fig. 1. 



Snout veiy long and narrow, the distance of its extremity from 

 the gill-opening being considerably less than that of the latter from 

 the origin of the dorsal fin ; the extremity and margin of the snout 

 densely covered with short bristles. 



Caraccas. 



2. Acestra oxyrhyncha. 



K)ier, Loricar. p. 31. taf. 8. iig. 2. 



Snout exceedingly long and narrow, the distance of the gill-opening 

 from its extremity being more than that of the former from the origin 

 of the dorsal tin. Margin of the snout Avith bundles of bristles, lon- 

 gitudinally arranged. Three longitudinal series of scutes on the 

 belly ; nineteen scutes between the base of the dorsal fin and the root 

 of the caudal. (Kner.) 



Rio Mamore. 



8. Acestra amazonum. 



Snout exceedingly long and narrow, the distance of the gill-open- 

 ing from its extremity being equal to that of the former from the 

 origin of the dorsal fin ; snout entirely covered Avith small, rather 

 tubercular scutes, without bristles. The length of the head (to the 

 end of the occijntal shield) is one-fourth of the total (with the caudal 

 fin) ; eye round, small, its diameter being one-fourth of the width of 

 the interorbital space. Seven scutes between dorsal fin and occiput, 

 twenty-three between dorsal and caudal. Thorax aud belly with two 

 longitudinal series of large scutes. L. lat. 3-4. Tail much depressed, 

 P. 1/6. V. 1/5, the outer ray rather thick and smooth. D. 1/6. A. 6. 

 Fins with brown dots. 



River Amazons. 

 It. Ten inches long. Santarem. From Mr. Bates's Collection. — This 

 specimen is not in a good state of preservation, and has the 

 caudal fin mutilated. 



4. Acestra gladiolus. 



Snout exceedingly long and narrow, sword-shaped, the distance 

 of the gill-opening from its extremity being more than that of the 

 former from the origin of the dorsal fin ; snout entirely covered with 

 rather smooth shields, without any bristles. The length of the head 

 (to the end of the occipital shield) is scarcely more than one-third 

 of the total (without caudal) . The soft parts surrounding the mouth 

 are situated in an elliptical cavity, which is two-thirds as broad as 

 long ; the maxillary barbel is rather short, and the posterior labial 

 fold moderately developed. Eye round, small, its diameter being 

 one-third of the widtli of the interorbital space. Scutes with small 

 granulations longitudinally arranged ; occipital shield with two slight 

 divergent keels posteriorly. Seven scutes between dorsal fin and 

 occiput, twenty-two between dorsal and caudal. The space between 



