66 PROCEEDINGS OF THE ACADEMY OP 



POMOXYS PKOTACANTHUS Gill. 



D. VI. 15. A. VI. 17. 



6 



Scales (1330) 43. 

 14 



The Pomoxys protacanthtis may be at once distinguished among the other 

 Bpecies here enumerated by the comparative elongation of the anterior dorsal 

 and anal spines. A single specimen (4565), from Tarboro, North Carolina, 

 is in the Smithsonian collection, and has no opercular spot. The absence of 

 this latter furnishes another specific character, unless it has been obliterated 

 by the alcohol. 



The following table gives the relative proportions of the several species : 



4564 4563 4565 



Extreme length 8 6| 6| C 



Body Greatest height 35 31 29 29 



Heightof tail behind anal fin 14 12 11$ 13 



Least height of tail 11$ 10 9* 10 



Length of tail 11$ 13 15 13$ 



Head Greatest length 31 29 29 28 



Height at pupil 15.} 14 14 15 



Length of snout 6} 6 6 6$ 



Orbit Diameter 5.} 6 6 6 



Dorsal Length of base 27 25 24 24 



Height at first spine 3 2} 2$ 4$ 



Height at last spine 11$ 13} 14 12 



Height at longest ray 16 16 16 



Anal Height at first spine 4 2$ 2$ 3} 



Height at last spine 9$ 12 11 10" 



Caudal Length of middle rays 17 18 17 19} 



Length of external rays 21 22 22 24 



Pectoral Length 16} 17 17 16 



Ventral Length 15 15 15 14 



On the Genus CAULOLATILUS, 

 BY THEODORE GILL. 



CAULOLATILUS Gill. 



*=CauloTatilas Gill, Proc. Academy of Natural Sciences, of Philadelphia, 1862, 

 p. 340. 



Dekaya Cooper, Proc. California Academy of Natural Sciences, iii. p. 70, 1864. 

 Latilus sp. Car. et Val. 



Body much compressed, elongated, with the height nearly uniform to the 

 anus ; thence gradually decreasing to the caudal peduncle, which is moderately 

 narrowed. 



Scales small, oblong, with a rather large central, minutely granular and 

 estriate area, from the posterior portion of which the rhipidal ridges radiate ; 

 and with a wiflo muricated posterior border ; the exposed surfaces are vertical, 

 especially near the head. 



Lateral line indistinct, parallel with the back ; median on the caudal 

 peduncle. 



Head compressed, scarcely oblong, with the profile boldly decurved, the 

 forehead flattened. Forehead behind cheeks and opercula, except interoper- 

 uilum, covered with ctenoid scales like those of the body. Eyes subcircular, 

 large. Preorbital bone cUnyated rhomboid, with the height less than the di- 



[April, 



