120 Zoology of Colorado 



fins. When we see a fish in which the sides have red spots sur- 

 rounded or ocellated by white, and the tail is without black 

 spots, it is the European trout (5. far to of Linnaeus) purposely- 

 introduced. Our American species do not have these ocellated 

 markings, but only black spots. The native Colorado forms 

 have a bright red mark on each side of the throat along the edge 

 of the lower jaw. In S. clarki stomias, of the Arkansas-Platte 

 drainage, the spots are comparatively few and large, mainly 

 in the region of the tail; in S. c. spilurus of the Rio Grande valley 

 the spots are numerous, of moderate size, and there is usually 

 a pink or reddish lateral band. S. c. pleuriticus, from the western 

 slope, differs from the last by the smaller scales, darker color, 

 and very numerous spots over the entire body. A form of the 

 Rainbow Trout (S. irideus shasta of Jordan) is now common in 

 Colorado. It lacks the distinct red marks on the throat, the 

 sides have a broad orange or red band, and the ventral, anal and 

 dorsal fins are tipped with white or yellow. The tail fin has 

 black spots, which are lacking in the also introduced Landlocked 

 Salmon (S. sebago). 



The Catfishes (Siluridae) are well known by their general 

 appearance, barbels (whence their common name) and total ab- 

 sence of scales. In the Channel Cat (Idalurus punctatus of 

 Rafinesque) the tail is deeply forked; the fish is found in the 

 Platte and Arkansas Rivers. A different Channel Cat, not yet 

 certainly identified, is said to exist in the Rio Grande at Ala- 

 mosa. The Bullhead (Ameiurus melas of Rafinesque) has the 

 tail scarcely or not notched, and is a smaller fish. It is frequent 

 in ponds and lakes in the eastern part of the State. Another 

 species (A. nebulosus), more lengthened and growing to 20 inches, 

 has been introduced in ponds and reservoirs. For critical de- 

 termination it is necessary to count the rays in the anal fin, 22 

 or 23 in A. nebulosus, 18 or 19 in A melas. The suckers (Catos- 

 tomidae) have soft fins, the dorsal with ten or more rays, and the 

 mouth usually inferior rather than terminal, suggesting the 

 common name. On the eastern side of the mountains we have 

 only three kinds, belonging to two genera. The short and deep 

 body, and long dorsal fin, readily identify the Quillback (Carpio- 

 des cyprinus of LeSueur*), which has been taken by Professor 



♦Generally known aa C. velifer of Rafinesque, but Professor C. L. Hubbs tells me that 

 our fish is distinct from true velifer, and is to be called C. cyprinus. 



