2Y6 PROCEEDINGS OF THE ACADEMY OP 



coloration from the C. knerii^ Gill, from Trinidad, W. I. Nu- 

 merous specimens. 



DIANEMA, Cope, gen. nov. 



Allied to Gallichthys. A single barbel at the extremity of each 

 maxillary bone ; two barbels at the symphysis of the mandible ; 

 teeth minute, brush-like. Body shields in two series, as in 

 Gallichthys ; postcoracoids dilated into two shields which meet on 

 the median line and involve the derm, as in Hoplosternum. Sides 

 of the face not shielded ; parietal not reaching base of dorsal fin, 

 but separated by two transverse shields of the sides. Dorsal and 

 pectoral fins with powerful spines, caudal subtruncate. Adipose 

 fin present, pungent. 



This new genus, it will be seen, combines in an interesting 

 manner the characters of Hoplosternum^ Gill, Brochis, Cope, and 

 Corydoras, Lac. The shielding is of the first, and the fin radii of 

 the last two, while in the peculiar barbels it resembles no other. 

 The relation of these to the double maxillary barbels of Corydoras 

 appears to be explained by the structure in the genus Brochis, 

 and will be mentioned under that head. 



DIANEMA LONGIBAKBIS, Cope. 



Form rounded compressed; head depressed, wide, but abruptly 

 narrowed in front of the nares. Maxillary barbels not reaching 

 the opercular margin, mental to the middle of the pectoral fins. 

 Shields 25-24, azygos four, all nearly smooth. Radii D. I. 7 I.; 

 C..12; A. t; Y. 7 ; P. I. 6. The pectoral spine is long and 

 straight, terminating in a point, and is finely and strongly serrate 

 on the inner, and finely bristled on the outer faces. Dorsal spine 

 acute, not serrate. Length of head 3.66 in length without caudal 

 fin, equal depth at dorsal fin. Postorbital width equal .70 length 

 of head, width at nares equal length from muzzle to orbit ; orbit 

 3.75 times in head, 2.5 times in interorbital width. Total length 3^ 

 inches, or .09 m. Color light yellowish-brown, fins unspotted. 

 The specimen has, however, lost all coloration it might have had, 

 in the spirits. 



The dorsal spine is less developed than in the species of Go7'y- 

 dorus. The posttemporal region is perforated by a few pores. 



[January 16, 



