47 



{Lepidox)setta bilineata), sharing with it the characters of rough scales 

 and lateral line considerably arched above the pectoral fin. From 

 that species it may be very readily distinguished by its color, which 

 is of a dark uniform slaty brown, and from all other species by the 

 combination of the two characters first mentioned, together with its 

 regularly ovate form and small, quite laterally-placed eyes. It does 

 not appear to be very common, as there are rarely above two or three 

 specimens among a miscellaneous heap of flat-fishes, and the usual 

 size does not exceed ten or eleven inches in length. From its small 

 size and comparatively unfrequent occurrence it cannot be consid- 

 ered as of great value from an economic point of view. It is sold 

 along with other species as "sole," and fetches the same price. The 

 extent and boldness of the arch of the lateral line varies greatly. 



SUBORDER ISOSPONDYLI. 



This suborder is the Physostoyni or Malacopteri of Cuvier and the older naturalists, minus the 

 Nematognathi or Silurians; the Haplomi (pike-toothed minnows, etc.), and the Eventognathi or 

 carp-like fishes. The fins are without spines (except one or two in dorsal or anal), the ventral 

 has no spine, the scales are cycloid, the head is naked, and an adipose fin is present behind 

 the true dorsal in some, while others have a serrated abdomen. The families, genera, and 

 species included in this suborder are more numerous than those in any other, the Acanthopie7-i 

 alone excepted, and among these families are two which, in their value to man, probably exceed 

 any other, namely, the SalmonidcE and the Clupeidce. 



Of the remaining families one only, the Sijnodontida;, sends a member to our markets in the 

 person of Synodon lucioceps, Ay res, which is not improbably identical with Sonodon (Saurus) 

 fceteus, Linn, a species known to occur upon the Pacific coast of Panama. In September and 

 October, 1878, numerous specimens of this species occurred in the market, most of them eight 

 to ten inches in length, but one individual reached seventeen and three-fourths inches. It is 

 occasionally taken in the bay. 



SALMONID/E. 



The Sahnonidfx are by far the most important group of fishes on this coast. The species of 

 greatest value belong to the genera Oncorhi/nchus, Salar, and Salveiinus. These will not be 

 treated of here. The single species of Coregonus that is known to inhabit the fresh waters of the 

 State is not brought to market, so the only salmonoids remaining for our notice are the small 

 marine fishes forming the group of the Microstomatidce. All the Salmonida: have an adipose 

 fin; the maxillaries enter into the formation of the lateral part of the ujjper jaw; the belly is 

 rounded and without serratures, and the air bladder is large and simple. 



Hijpomesus olidus— This delicate fish is, at first glance, similar to 

 the following species, but the mouth is very small, the end of the 

 maxillary bone reaching only level with the front of the eye, while 

 in Osmerus thaleichthys it reaches to the back of the orbit. The head 

 also 'is somewhat smaller. But this fish, when fresh, can be most 

 readily distinguished by the transparency of its flesh, which, of course 

 disappears entirely in preserved specimens. The silvery band along 

 the sides, which is found in all the four species, and is probably the 

 cause of their being grouped together as smelts, is particularly bright 

 in this fish. This species has been tolerably abundant in our mar- 

 kets from October to August. In size it is usually somewhat larger 

 than Osmerus elongatus or Osmerus thaleichthys, attaining a length of 

 about eight inches. 



Osmerus thaleichthys is really the nearest representative of the smelt 

 of Europe, having the peculiar, pleasant smell that suggests the name 

 in that species, which is also a kind of Osmerus. It may readily be 

 distinguished from the two species of Atherinidse, Chirostoma calijor- 

 niensis, and Atherinops affinis by the want of spinous rays on theback, 

 by the adipose fin, by the absence of the bright green tint, which is 

 replaced on the back by a dull, greenish olive, on which a diamond 



