NATURAL SCIENCES OP PHILADELPHIA. 147 



and S. viviparus, which have " fifteen" dorsal spines, and which are indeed the 

 types of the genus, but that gentleman has shown his appreciation of the 

 value of the character, and has only been unhappy in its application : he 

 should have given a new name to the genus defined by him. Dr. Ayres has 

 omitted to inform his readers that the difference in the number of dorsal spines 

 is also supported by a corresponding difference in the number of vertebrae, 

 the species of " Sebastkhthys having, as far as known, only ten abdominal and 

 fourteen caudal vertebrae,"* while Sebastes has about twelve abdominal and 

 nineteen caudal vertebrae.f 



The value of the characters used to distinguish the genera Sebastes, Sebas- 

 tichthys and Sebastodes is now indeed so generally conceded by scientific men, 

 that it is unnecessary to further argue in their favor. I shall only remark 

 that the combinations and distinctions of forms by Dr. Ayres are alike un- 

 natural and violate all natural affinities, and that the distinctions used by 

 him to separate his genera Sebastes and Sebastodes are only of secondary value. 

 More acquaintance with the species of the family would undoubtedly con- 

 vince him of the justness of this assertion. 



Dr. Ayres has been unfortunate in at least one of his identifications, connect- 

 ing Girard's name Sebastes rosaceus with a species of " Sebastodes," with the 

 remark that " this is the species originally described by Girard under the 

 name rosaceus; and again, quite correctly, in the tenth volume of the 'Pacific 

 Railroad Reports.'" Yet S. rosaceus is said to have "the upper surface of 

 the head with horizontal and acute ridges," and is figured with such arma- 

 ture as well as with the second, instead of the third, anal spine longest, 

 the pectoral and ventrals ceasing before the vent, &c. ! Girard's Sebastes rosaceus 

 is indeed a typical Sebastes of Ayres, and entirely identical with the . helvo- 

 maculatus of the latter, as the examination of the two specimens known to 

 Girard has convinced me. The specimens are in poor condition, but the 

 spots are still visible. The Sebastodes rosaceus of Ayres is therefore deprived 

 of a name, and may receive that of Sebastosomus% pinniger. 



It is also proper to here remark that two species are apparently confound- 

 ed by Girard under the name Sebastes melanops, one with, "a small spine upon 

 the suprascapular bone, two others upon the edge of the opercle," and another 

 from Cape Flattery with the lower opercular spine as well as the supraorbital 

 ridges obsolete, and the forehead between the eyes perfectly arched. The 

 latter may be named Sebastosomus simulans. 



In conclusion, the genus Sebastkhthys includes at least three genera. The Se- 

 bastkhthys nigrocinctus is somewhat related to Scorpiena, and distinguished by 

 elevated, serrated coronal crests. Other Californian species represented by the 

 Sebastes melanops, seen by me, differ so much that they may be separated and 

 combined for the present under a genus Sebastosomus, of which the Sebastes 

 melanops of Girard may be taken as the type. Still others, distinguished by 

 the texture of the bones of the skull, armed orbital ridges, prefrontals, &c, 

 and represented by Sebastes rosaceus, Grd., may be named Sebastomus. In a 

 contemplated Monograph of the Scorpaenoids of California, the relations of 

 the species will be more fully discussed. 



Second Contribution to the SELACHOLOGT of California. 



BY THEODORE GILL. 



Since the publication of the article " On the Classification of the Families 

 and Genera of the Squali of California, " additional information has been 



* Gill, Proceed. Acad. Nat. Sci., Phila., 1862, p. 278. 



t The increase in the number of vertebrae in the species of Sebastes. a genus peculiar to the 

 Northern Seas, affords an excellent example of the truth of the generalization claiming an 

 increased number of vertebrae for the cold-water representatives of the families of Acanthoptery- 

 gians. 



J Sebastosomus, Gill. Type Sebastes melanops, Girard. 



y Proc. Acad. Nat. Sciences, Phila., 1862, pp. 483501. 



1864.] 



