386 



BULLETIN OF THE BUREAU OP FISHERIES 



Zenithicus may be separated from reigJiardi by its greater number of gill rakers 

 and lateral-line scales, longer snout, and less depth of head and body. These char- 

 acters are compared for the two species below: 



Gill rakers : 



zenithicus, (33) 36-39 (42), with 78 per cent more than 36. 



reighardi, (32) 33-36 (38), with 9 per cent more than 36. 

 Lateral-line scales: 



zenithicus, (66) 70-77 (83), with 55 per cent more than 73. 



reighardi, (64) 66-73 (77), with 15 per cent more than 73. 

 H/S: 



zenithicus, (3) 3.2-3.4 (3.8), with 19 per cent more than 3.4. 

 reighardi, (3.3) 3.5-3.6 (4), with 85 per cent more than 3.4. 

 L/HD: 



zenithicus, (5.8) 6.1-6.8 (7.4), with 84 per cent more than 6.2. 

 reighardi, (5.5) 5.7-6.2 (6.6), with 10 per cent more than 6.2. 

 HD/S: 



zenithicus, (1.8) 1.9-2.1 (2.3), with 6 per cent more than 2.1. 

 reighardi, (2) 2.2-2.3 (2.7), with 83 per cent more than 2.1. 

 L/D: 



zenithicus, (3.5) 3.7-4.5 (5), with 55 per cent more than 4. 

 reighardi, (3.5) 3.6-4.1 (4.4), with 14 per cent more than 4. 



Zenithicus has also a somewhat smaller head, a more compressed body, and 

 shows less pigment throughout. The maxillary is usually pigmented over only 

 one-fourth or less in zenithicus and at least one-third its extent in reighardi; and all 

 the abdominal fins are immaculate in over two-thirds of the individuals of zenithicus, 

 while two-thirds of the specimens of reighardi examined have some pigment. 



From nigripinnis regalis, zenithicus differs, in addition to the lower gill-raker 

 number, in having less body depth and a much more elliptical body outline as seen 

 from the side; in having much less pigmentation on body and fins, a smaller eye, longer 

 snout, and shorter pectorals. Certain of these characters are compared below: 

 L/D: 



zenithicus, (3.5) 3.7-4.5 (5), with 55 per cent more than 4. 

 nigripinnis, (3.1) 3.5-4 (4.5), with 16 per cent more than 4. 

 H/E: 



zenithicus, (3.6) 4-4.4 (4.6), with 60 per cent more than 4.1. 

 nigripinnis, (3.5) 3.7-4.1 (4.3), with 4 per cent more than 4.1. 

 H/S: 



zenithicus, (3) 3.2-3.5 (3.8), with 9 per cent more than 3.5. 

 nigripinnis, (3.4) 3.6-3.8 (4.3), with 94 per cent more than 3.5. 

 Pv/P: 



zenithicus, (1.5) 1.6-1.9 (2.1), with 69 per cent more than 1.6. 

 nigripinnis, (1.2) 1.4-1.6 (1.9), with 7 per cent more than 1.6. 



The mandible, in relation to the upper jaw, is shorter in zenithicus, and the 

 head, seen from the side, is much more elongate and less distinctly triangular. 



Only small individuals can be confused with hoyi, as the latter does not often 

 grow larger than 200 millimeters; and almost always they can be separated from 

 hoyi by their shorter mandible (which in hoyi, in addition to being longer, usually 

 has a distinct symphysial knob), less depth of head and body, and fewer gill rakers, 



