246 PROCEEDINGS OF THE ACADEMY OP [1886. 



Giisterosteus plebeins Giranl, "Proc. Ao. Nat. Sci. Phila., 1854, 147;" 



Girarrl, Pacific R. R. Survey, 86, 1859 (San Francisco ; San Jose ; 



Petaluma) ; Sauvage, Revision des Epinoches, 18, 1874 (Petaluma) ; 



Jordan, Cat. Fresh-water Fish. N. A., 442, 1878 (Name only). 

 Gasterosiei/x inopinatus Girard, " Proc. Ac. Nat. Sci. Phila., 1854, 147;" 



Girard, Pacific R. R. Survey, 90, 1859 ^Presidio); Sauvage, Revision 



des Epinoches, 19, plate i, fig. 4, 1874 (Presidio Creek, Cal.j; 



Jordan, Cat. Fresh-water Fish N. A., 443, 1878 (Name only). 

 Gasterosteus pugetti Girard, "Proc. Ac. Nat. Sci. Phila., 1856, 135;" 



Girard, Pacific R. R. Survey, 92 and 354, 1859 (Puget Sound); 



Jordan, Cat. Fresh-water Fish N. A., 442, 1878 (Name only). 



Habitat. Pacific Coast North America, from Bering Strait 

 south to Todos Santos Bay. Ascends rivers. 



This species differs from dimidiatus in having no cusp at base of 

 ventrals and no caudal keel ; it differs from wheatlandi in haA'ing 

 all its bones much weaker and in the arrangement of the mucous 

 lucres about the head. 



The collection of Jordan and Gilbert shows that all naked- 

 tailed Sticklebacks {microcephalus, plebeius, inopinatus and 

 pugetti) belong to one species. 



It is possible, as several writers have affirmed, that all these 

 naked-tailed Sticklebacks {gymnurus, mici^ocephalus, ivheatlandi, 

 williamsoni) are simple varieties of the ordinary G. acideatus. 

 It seems to me that the peculiarities of the Californian form are 

 so constant that we may regard this one at least as presenting 

 a distinct species. Of G. wheatlandi and gymnurus I am not so 

 certain, but I have not yet seen any distinctly intermediate 

 forms, although all these types, like all other Sticklebacks, are 

 subject to much individual variation. The characters given in 

 the analysis above are to be regarded as simply provisional, as 

 representing the differences shown by the material at my disposal. 



The specimens examined by me are from San Diego, Cal. 



6. Gasterosteus wheatlandi. 



Gasterosteus wheatlandi Putnam, "Proc. Essex Inst., v. 4, 1867;" 



Storer, Hist. Fish. Mass., 354, 1867 (Nahant). 

 Gasterosteus trachurus Goode & Bean, Fishes of Essex Co. and Mass. 



Bay, 5, 1879 (Nahant, not G. trachurus of G\i\\er). 



Habitat. East Coast United States, northward. 



This species difiers from G. microcephalus in having stronger 

 surface bones, no mucous pores about the head, and the caudal 

 peduncle compressed. 



The specimens examined by me are from the coast of Massa- 

 chusetts. 



