Occasional Papers of the Museum of Zoology 3 



differs notably from all other specimens collected at San Antonio, and 

 would unhesitatingly be considered a species distinct from the other 

 specimens from the same locality. But at Palacios the same form 

 branching from the Calabazar form approaches the characters of the 

 single specimen from San Antonio. 



In other words, the variations have at most an imperfect 

 geographical significance. The variations in form possibly are 

 sexual, for some large individuals are slender, while others are 

 robust; the variations in color are perhaps in part correlated with 

 sex, and imperfectly with age. Most of the variations, however, 

 seem to be of an individual, rather than racial, sexual, or age, 

 character. 



Cichlasoma tetr acanthus was described by Valenciennes in 1831, 

 under the name of Centrarchus tetracanthus. Although Guichenot 

 listed this name in 1853, he also described the species from Cuba, in 

 the same work as Chromis fusco-maculata — a name later adopted 

 by Gunther and by Pellegrin. These two names were apparently 

 based on similar examples of this variable cichlid, belonging to the 

 type called Heros tetracanthus tetracanthus by Eigenmann. Eigen- 

 mann based five additional names upon Cuban cichlids, all of 

 which Regan has synonymized, without remarks, with tetracanthus. 

 These five nominal forms may be treated separately. 



Heros tetracanthus torralbasi, as well as the type B and C of 

 typical tetracanthus, seem to be based on individual modifications 

 of the same fundamental color pattern. Both types occur together, 

 and in specimens of either type the characteristic markings of the 

 other show more or less distinctly. 



Heros tetracanthus griseus is based upon one of the specimens 

 from San Antonio with a comparatively large eye and gray, 

 faintly marked coloration; the size of the eye falls well within the 

 limits of variation ascribed to the species by Regan, and the 

 coloration appears to be nearly matched by individuals of tetracan- 

 thus from other localities. 



