432 ADDENDA. 



its greatest width is two-thirds of its length. Snout very obtuse, 

 subsemicu-cular, with the upper jaw longer ; the anterior margin of 

 the eye is nearer to the extremity of the snout than to the end of the 

 operculum. The stylrform maxillary is prolonged into a very small 

 barbel, not fringed, hidden in a groove, and not extending to the 

 an^le of the mouth. Each band of teeth in the upper jaw is much 

 broader anteriorly than in the middle of its length. Eye rather 

 laro'e, its diameter being two-thii-ds of its distance from the posterior 

 nostrU. Dorsal spine slender, not quite half as long as the head, 

 finely serrated anteriorly ; pectoral spine flexible ; the poms axil- 

 laris is wider than the anterior nostril, and closed by a membrane 

 perforated by many smaller foramina. Caudal fin obliquely emargi- 

 nate. The pectoral does not extend to the ventral, which reaches 

 the anal. Upper and lateral parts brownish, with several indistinct 

 whitish bands along the side. Dorsal fin and upper side of pectoral 

 with irregular blackish-brown spots ; basal half of the caudal black, 

 the remainder white. 



Surinam. 

 a. Twelve and a half inches long. From the Stuttgart Museum. 



Page 192. Ageniosus dentatus. 

 Read : ? Silurus inermis, JBloch, t. .363, instead of t. .366. 



Page 248. Chaetostomus calamita. 

 b~d. Male and females. Rio Apurimac. From Mr. Pentland's 

 Collection. 

 The four specimens which we possess of this species are 5 inches 

 long, two being males and two females ; the former alone have the 

 snout covered with tentacles, whilst the females have no tentacles 

 whatever on the soft margin of the snout ; therefore it is evident 

 that the tentacles are a sexual character, and that great caution is 

 necessary in determining specimens of this geniLS. 



Page 249. Chaetostomus erinaceus. 



Figured in Gay, Hist. Chile, Zool. ii. p. 308. lam. 6 bis, fig. 2. 



Page 254, note. 



Loricaria scolopacina, Filippi, is probably a species of Acesfra, perhaps iden- 

 tical with A. acus, to the synonymy of wliich it has been referred at p. 261. 



Page .308. Leporinus pachynrus. 

 h. Adult : stuffed. Rio Jocintins. Purchased of Mr. Gardiner. 



