57§ CALIFORNIA ACADEMY OF SCIENCES. IO 



rosacens, ruber, constellatus, etc., with concave interor- 

 bital space, straight base of skull, and strong spines and 

 ridges; and miniatus and pinniger with convex interorbi- 

 tal space, curved base of skull, weak spines and ridges 

 and depressed mesethmoid processes. In every point of 

 structure and conformation of skull the last two species 

 are most closely related to the species placed in the gen- 

 era Primospina, Sebastosonuts and Acutomentum ; and 

 are widely separated from the other species of the genus 

 Sebastomus. 



The condition of the parietals was the first character 

 selected by the writer as a basis for the arrangement of 

 the species, but it was soon found unreliable from every 

 point of view and had to be rejected; and the further the 

 investigation proceeded the more clearly was its rejection 

 justified. An examination of all the cranial characters in 

 a large number of species will invariably lead to the same 

 result. 



Of the fifty or more species recognized from the Pacific 

 Coast of America, the following thirty-two have been ex- 

 amined by me : S . paucispinis, goodei, mystinus, mela- 

 nops, favidus, entomelas, ovalis, atrovirens, pinniger, 

 miniatus, introniger, aurora, chlorostictns, rosaceics, con- 

 stellatus, rkodochloris, ruberrimus * saxicola, dip/oproa, 

 elongatus, rubrivinctus, levis, serriceps, rastrelliger, auri- 

 culatus, vexillaris, cdurinus, maliger, camatus, chrysom- 

 elas and nebulosus; besides two or three unidentified 



* The specific name ruberrimus is here proposed as a substitute for the 

 ruber of recent authors, not of Ayres, which latter must be regarded as 

 a synonym of auriculatus. That the specimens to which the name ruber 

 was first applied belonged to the species auriculatus is clearly shown by the 

 careful description of the spines on the top of the head. The statements 

 concerning color and size do not apply to auriculatus, but apply equally 

 well to each of the three species ruberrimus, pinniger or miniatus. (Ayres, 

 Proceedings California Academy of Sciences, vol. i, p. 7, 1854.) 



