NOTES ON THE OCCURRENCE OF GILLICHTHYS Y-CAUDA AT SAN 

 DIEGO, CALIFORNIA. 



BY 



Charles H. Gilbert. 



Professors Jenkins and Evermann have recently described from 

 Gnayiuas, Mexico, a very interesting Goby (Gillichthys y-cauda), dis- 

 tinguished, among other points, by having but tive dorsal spines. The 

 extension of the range of this species to include the entire Gulf of Cal- 

 fornia region was to be looked for, but its discovery as far north as 

 San Diego was unexpected. On examining recently a bottle of small 

 Gobies (No. 2486G), labeled Gillichthys mirabilis, collected by Jordan 

 and Gilbert in 1880, at San Diego, I found the collection to consist in 

 equal parts of Gillichthys y-cauda and Lepidogobius gilberti, the latter 

 a species recently described by Mr. C. H. Eigeumann from San Diego 

 Bay. 



A second lot (No. 31904), collected by Mrs. C. H. Eigenmann, contains 

 the same two species, which must be about equally abundant at San 

 Diego. 



In all specimens of G. y-cauda examined, including the types, I find 

 the dorsal V-15 or 16, the anal 14 or 15. G. guaymasim Jenkins and 

 Evermann, also from Guaymas, has the same number of fin rays, the 

 types in the Museum showing D. V-16 ; A. 14. I can discover no impor- 

 tant difference between the two species in general proportions, or in 

 size of eye and mouth, and am in some doubt as to their distinctness, 

 although they seem to differ somewhat in coloration. 



An examination of the types of Gobius townsendi Eigenmann and 

 Eigenmann, has shown it to be based on the young of Gillichthys mira- 

 bilis. In the largest specimens the elongation of the maxillary has 

 become evident. The flu formula of mirabilis is D. VI-12 to 14; A. 12 

 or 13. 



U. S. Fish Commission, August 28, 1889. 



Proceedings National Museum, Vol. XII— No. 774. 



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