34 



found the shallow water species under one common title. The spines 

 upon the top of the head are mosl developed in 8. nigrocinctus, and 

 in this respecl S. serriceps comes next. Both are rare in the markets 

 of San Francisco; the firsl the rarer, and both are black-banded. In 

 the attempt to give his fish a descriptive name, Ayres called the 

 former nigrocinctus, or black-banded, a name which applies better to 

 the second species; while serriceps or sawhead would fit nigrocinctus 

 q better than it fits the species to which it is applied. Ayres 

 observed serriceps as long ago as 1859, for he remarks to this effect: 

 "There is in the markets occasionally another fish of the nigrocinctus 

 type which may eventually prove distinct." The spines or spinous 

 ridges on the head of the fishes of this genus are an anterior pair upon 

 the snout (nasals,) a posterior pair on the back of the head (occipitals,) 

 and between these three pairs which, from their position, are called 

 pre-ocular, supra-ocular, and tympanic. A pair of post-oculars, dis- 

 membered from the supra-oculars, is often present, and some have a 

 pair of spines called " nuchal," behind the occipitals. In nigrocinctus 

 the nuchal and tympanic pairs are wanting, but the others rise into 

 high ridges with undulating or jagged edges. In serriceps the nuchal 

 pair is present, and all the ridges end posteriorly in sharp spines ris- 

 ing well above the surface of the head. 



S. m bulosus, chrysomelas and carnatus are a trio of fishes exceedingly 

 similar in appearance, differing, in fact, only in coloration, and with 

 only one or two specimens of each to look at, it is difficult to believe 

 in their distinctness; yet. when one has seen lying, side by side, a 

 hundred examples of S. carnatus, all exhibiting red spots in almost 

 exactly the same positions of the yellow -ones of nebulosus, and when 

 one has seen a pile of chrysomelas with its characteristic broad yel- 

 low band from front of dorsal to tail, following nearly the same line 

 as the principal spots of the nebulosus, and when this color difference 

 has been correlated with certain differences in the form of the body 

 and head, it is difficult to avoid the conclusion that we have here 

 three distinct yet very closely related forms. 



S. maliger and S. vexillaris may be known from all others by their 

 very high spinous dorsal, with the membrane deeply emarginated 

 between each spine, and from each other by the bright chrome 

 yellow tint of the former. 



In all the foregoing species the jaws are equal in length or nearly 

 so, and the form of the body is short and thick ; the greatest depth 

 equal to or more than one third of the length of the fish. Nigro- 

 cinctus and chrysomelas are remarkable for the great width of the body 

 at the origin of the dorsal, and for the abruptly shelving form of the 

 nape and top of head. In the succeeding species the jaws are still 

 nearly equal, but the body is more elongated. S. rastrelliger may at 

 once be known by a glance at the gills, or rather at the gill-rakers, 

 or comb-like teeth set upon the inner or throat side of the bones 

 bearing the gills. In all the other species these are more or less 

 elongate, but in this they are often broader than they are long. This 

 is an exceedingly dark colored species, dark brown, clouded with 

 still darker, and the dorsal fin is very low. 



S. auriculatus, the common rock-fish of the bay, may be identified 

 by the black spot upon the tip of the gill-cover; S. rubrivinctus, which 

 rarely, if ever, comes to the markets of San Francisco, by the broad 

 transverse stripes of red and yellow upon its body; and S. ruber by its 

 dfeep uniform red tint, large size, and broad, flat preopercular spines. 



