NORTHERN CHIM.ERA. 



1.S-, 



one corresponding above. Nostrils immediately above the 

 upper lip contiguous, each with a cartilaginous complicated 

 valve. Branchial openings in front of the pectorals. Eyes 

 large, lateral. On the crown, in front of the eyes, a thin 

 osseous plate, bent forwards, with a spinous disc at the ex- 

 tremity on the lower side. Lateral line connected with nu- 

 merous waved anastomosing grooves on the cheeks and face. 

 The first dorsal fin above the pectorals narrow, with a strong 

 spine along the anterior edge. The second dorsal rises im- 

 mediately behind the first, is narrow, and is continued to the 

 caudal one, where it terminates suddenly. The pectorals are 

 large, and subtriangular. Ventrals rounded ; in front of each 

 a broad recurved osseous plate, with recurved spines on the 

 ventral edge. Claspers pedunculated, divided into three 

 linear segments ; the anteal one simple, the retral ones having 

 the opposite edges covered with numerous small reflected 

 spines. A small anal fin opposite the extremity of the second 

 dorsal. Caudal fin above and below, broadest near the origin, 

 gradually decreasing to a linear produced thread.'" 



The appendage on the front of the head in this fish is 



