60 PROCEEDINGS OF THE ACADEMY OF [1885. 



In the young specimens the head is more narrow and rounded, 

 and the lower branch of the subopercular spine proportionally 

 larger than in the adult. 



The deeper-water specimens are lighter in coloration than those 

 from near the surface, and those from the coral reefs are paler 

 than those from the green algae and sea-wrack, otherwise no dif- 

 ferences seem to exist. 



9 b. Batrachus tau pardus. 



Batrachus tau var. pardus Goode & Bean, Proc. U. S. Nat. Mus., 1879, 

 336 (Pensacola, Fla.); Jordan & Gilbert, Syn. Fish. N. A., 1883, 

 751. 



Batrachus pardus Goode & Bean, Proc. U.S. Nat. Mus., 1882, 336' 

 (Gulf of Mexico); Bean, Cat. Fish. London Exhibit., 1883, 47 (Pensa- 

 cola, Fla.); Jordan, Proc. Acad. Nat. Sci. Phila., 1884, 45 (Egmont 

 Key). 



Habitat. — Gulf of Mexico ; Egmont Key ; Pensacola. 



The coloration of ^tardus is very different from that of tau. In 

 the specimen (13| inches in length, from Pensacola) which we 

 have examined, the fleshy tentacle between nostrils is wanting, 

 while in all the specimens of B. tau this is present. 



The former seems to be a deep-water variety or subspecies of 

 the latter. The few specimens of pardus known are from con- 

 siderable depths. The texture of the flesh and the skin is less 

 firm than in tau. 



9 c. Batrachus tau cryptocentrus. 



Batrachus cryptocentrus Cuvier & Valenciennes, Hist. Nat. Poiss., 

 1837, 485 (Bahia). 



Habitat — Eastern Coast of South America (Bahia). 



This form is known only from the meagre description of Cuvier 

 and Valenciennes. We venture to place it among the varieties of 

 tau, as no diagnostic character of importance appears in the 

 description. 



4. BATRACHOIDES. 



Batrachoidcs Lacepede, Hist. Nat. Poiss., iii, 1798, 306 (Batrachoidcs tau 

 Lacopede = Batrachus surinamcnsis Bloch). 



This genus is closely allied to Batrachus, but it seems to be 

 sufficiently distinguished by the scaly body. Two species are 

 found in American waters. 



