SPAROID PISHES OF AMERICA AND EUROPE. 



521 



The specimens examined by Eigenmann and Hughes, now before us, 

 differ decidedly in the proportions, the color, and the size of the teeth ; 

 but while the differences of the extremes are very marked, the iuter- 

 gradation is so perfect that no tangible specific distinctions can be 

 made out. We have only the deeper form {flavoUneatus) from Key 

 West, while we have both extremes from Havana. As far as we are 

 able to judge from the tigures and the descriptions, the unimaculatus of 

 Bloch & Schneider, Cuv. «& Val., and Jordan & Gilbert, the caribccus 

 of Poey, and the Immerimaculatus Quoy & Gaimard represent the more 

 slender form, while the Jiavolineatus Cuv. & Val. represents the deeper 

 form. The differences of the extreme forms seem to be these: 



37te deeper form {flavoUneatus). 



Greatest deptb, 2 in length. 

 Ventral outline very mucli rounded. 

 Distance from insertion of first dorsal 



spine, obliquely to snout, IJ in 



depth. 

 Teeth about one-third narrower than in 



the more slender form. 

 Body more compressed. 



The more slender form (unimaculatus). 



Greatest depth, 2^ in length. 

 Ventral outline almost straight. 

 Distance from insertion of first dorsal 



spine, obliquely to snout, 1 in 



depth. 



120. ARCHOSARGUS POURTALESII. 



Sargus pourtalesii Steindachnor, Fische Afrikas, 39, 1881 (Galapagos Islands). 

 Archosargus pourtalesii, Jordan & Bollman, Proc. U. S. N, M. 1889, 18G (Chatham 

 Island of the Galapagos). 



Habitat: Galapagos Islands. 



Etymology: To Louis F. de Pourtales, a friend and associate of 

 Agassiz, who was with him on the Hassler expedition, by which this 

 fish was discovered. 



This species is known to us from the description and excellent figure 

 given by Dr. Steindachner and from a specimen obtained by the Alba- 

 tross on Chatham Island. The differences between pourtalesii and 

 unimaculatus are very slight, and might be ignored were it not for the 

 remote and rejrtricted habitat of the Pacific form. 



121. ARCHOSARGUS TRIDENS. 



Sargus iridens Poey, Enumeratio Pise. Cub., 57, 1875 (Cuba). 

 Archosargus tridens Eigenmann «Sr. Hughes, 1. c, 1887, 70 (copied). 



Habitat: Cuba. 



Etymology: Tres^ three; dens, tooth. 



This species is known to us only from the description of Prof. Poey. 

 Its distinctive characters need verification, it being perhaps an ab- 

 normal specimen of Archosargus unimaculatus. 



