ij , rrS.-.P. R. R. EXP. AND SURVEYS -ZOOLOGY GENERAL REPORT. 



which we have placed in the genus Glypliisodon, not having the means of determining it more 

 accurately. 



The chromids, or fresh water labroids, with pectinated scales, have not yet been met with 

 along the Pacific range of North America. We have evidences of their presence in the basin 

 of the Kio Grande del Norte or Rio Bravo, figured and described in Major Emory s &quot; Report on 

 the United States and Mexico Boundary Survey.&quot; 



The scomberesocids, on the other hand, are represented, so far, by a species of the genus 

 B clone. 



The gadoid family has given us a cod and a whiting. 



The pleuronectids, or flat fishes, are tolerably well represented, though we observe as yet 

 neither turbots (Rhombus) nor halibuts (Hippoglossus). 



The ophidioid family is represented by two known genera, OpJiidium and Ammodytes, whilst 

 the true eels have not yet been heard of. 



The salmonids are rather abundant, especially in species of the Linnean genus Salmo, to 

 which may be added a white fish (Coregonus), and two smelts, properly so called (Osmerus and 

 Argentina). 



No characini are known north of the valley of the Rio Grande del Norte (Rio Bravo), where 

 one species was collected by the United States and Mexico Boundary Commission, and in whose 

 report it will be figured and described. 



The scopelini have furnished us, so far, with one species of the genus Saurus or Laurida along 

 the Pacific coast. 



The fresh waters teem with cyprinoids and percoids, the former east and west of the Rocky 

 mountains, the latter only eastwardly, in the shape of sun-fishes (Pomotis) and bass, (Centrar- 

 chus^) a single species of the bass having been met with in California. 



Of the cyprinodont family we have mentioued but one species, an inhabitant of the fresh 

 waters of California. Those collected in the interior of the continent we propose to investigate 

 at some future time. 



The etheostomoids are likewise left aside for the present. 



Neither pikes, nor pickerels, or esocids have been observed west of the Mississippi valley. 



A few catfishes (Pimelodus) were procured at the initial point of the exploration of the 35th 

 and the 47th parallels, none having been found west of the Rocky mountains. 



Of the herring family, we meet with a true herring (Meletta), and two anchovies (Engraulis), 

 but as yet no shads (Alosa) have been seen in the collections made. 



The lophobranchs are represented by a few pipe fishes. 



So much for the osseous fishes. The cartilaginous, so far as observed, are anything but 

 numerous ; a few sturgeons, sharks, skates, and lampreys constitute the list we are for the 

 present acquainted with. Amongst sharks and skates there are curious genera : Cestracion, 

 Triakis, Rhinobatis, and Rhinoptera, whilst amongst lampreys we meet the ordinary genus 

 Petromyzon. 



