SOUTH AMERICAN NEMATOGNATHI. 31 



ANALYSIS OF THE SPECIES OF AILURICHTHYS. 



a. Dorsal spine not produced in a long filament; occipital process large, 



shaped like a clover leaflet; gill-rakers 5 -{-14; base of ventrals about 



equidistant from snout and caudal. panamensis 18. 



aa. Dorsal spine produced in a long filament; occipital process normal; 



gill-rakers not more than 9. 



b. Distance of dorsal fin from tip of snout 3J-4 in. the length; distance 

 of adipose from the dorsal fin 2| times in the length, or longer; base 

 of anal 4f in the length, or longer. 



c. Anterior lobe of anal with minute dots; highest anal ray less than 

 half the length of the base of the anal; vomeriue and palatine 

 patches of teeth separate; anal rays 32-35. bagre 19. 



cc. Anterior lobe of anal with a large dark blotch; highest anal ray 

 more than half the length of the anal's base; vomerine and palatine 

 patches of teeth joined; anal rays 28-30. pinnimaculatus 20. 



bb. Distance of dorsal from tip of snout 3 in the length; distance of ad- 

 ipose from dorsal fin 3 in the length; highest anal ray about as high 

 as the base of the anal, which is 5f-6 in the length; anal rays 20-24. 



marinus 21. 



18, Ailurichthys panamensis. 



jElurichthys panamensis Gill, Proc. Acad. Nat. Sci. Philad. 1863, 



172 (West Coast Central America); Giinther, Fish. Centr. Am. 



393 & 476, 1866 (Panama); Steindachner, SB. Ak. Wien, Ixxiv, 



1876, Ichthol. Beitr. iv, 14, plate ii, fig. 1-4 (Altata, Panama, 



Magdelena Bay); Jordan & Gilbert, Bull. U. S. Fish Comm. 



1882, 37 (Panama); Jordan & Gilbert, Proc. U. S. Nat. Mus. 



1882, 622 (Panama); Jordan, Proc. U. S. Nat. Mus. 1885, 365 



(name only); Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. vol. i, 



1888, 148 (Panama). 

 sElurichthys nuchalis Giinther, Cat. Fish. Brit. Mus. v, 179, 1864 



(Pacific Coast 'Panama); Giinther, Fish. Cent. America, 393 & 



476, plate Ixxxi, fig. 2 (Panama). 

 Habitat: West coast of Central America and Mexico. 



Body rather robust, the depth under the dorsal spine 

 scarcely greater than the width. Head short, its depth 

 at the base of the occipital process equal to its greatest 

 width, 1J in head. Fontanel narrow, prolonged as a 

 groove to the base of the occipital process which is vari- 

 able in form, in the male like a clover leaflet, as broad 

 as long, obtusely keeled. Profile steep. 



Eye large, 1^ in snout, 1J in the interorbital, 3-4 in 

 the interocular, 4|-5i in the head. 



