i 3 8 



PAPERS FROM TORTUGAS LABORATORY 



VOL. XXXIV 



Eucinostomus gula (Cuvier and Valenciennes) 



Genres gula Cuvier and Valenciennes, Hist. nat. poiss., vol. 6, 1830, p. 464 — Martinique. 

 Diapterus (species dubia) Poey, Repertorio, vol. 2, 1868, p. 324 — Havana. 

 Eucinostomus gulula Poey, Enumeratio, 1875, P- 54> P^ - — Havana. 



Diapterus hornonymus Goode and Bean, Proc. U. S. Nat. Mus., vol. 2, 1879, p. 340 — Clear- 

 water Harbor, Florida. 



The types of Gerres gula, collected by Plee in Martinique, are 2 fish of which 

 the proportional measurements are given (first) in table 6. They are representa- 

 tives of a species usually distinguishable by having a scaleless pit over the tips of 



TABLE 6 



Measurements (in millimeters) of 7 specimens of Eucinostomus gula, the first 2 being 



THE TYPE SPECIMENS 



(The figures in parentheses in the third and fourth columns show the number of times the 



depth and head, respectively, are contained in the standard length. Those in the last column 



show how many times the eye is contained in the head.) 



the premaxillary processes, rather than a scaleless premaxillary groove open an- 

 teriorly, as in Eucinostomus argenteus and some if not all the other species of 

 the genus. 



In the museums it is not uncommon to find "Eucinostomus gula and E. ar- 

 genteus confused. But even if scales in the critical region are lost, or if individual 

 variation produces intermediates as to squamation, as it possibly does, the two 

 (quite independently of differences in proportions) are still separable by slight 

 but constant differences in the structure of the functional first interhemal. For 

 example, in proportion to its length the diameter of the interhemal cavity is much 

 greater in E. gula than in E. argenteus, and, furthermore, the ridge from the 

 articular extremity of the second interhemal (morphologically speaking) runs 

 laterally in the former, rather than posterolateral^ as in the latter species, on the 

 composite first and second, and does not continue so far from its origin as an 

 evident ridge. 



Atlantic coast of tropical America, sometimes straying northward to Cape Cod. 



W.H.L. 



