ANALYSIS OF SPECIES OF MYXOSTOMA. 117 



.dps distinctly plicate Continued. 



cc. Scales very small for the genus, about 9-56-8 in number : body moderately 



elongate, the depth about 4 in the length. 



ee. Head shortish, conic, the snout not much projecting, about 4 in length : 

 eye large : dorsal tin small, with about eleven rays, the last rapidly 

 shortened (characters of mouth unknown, but probably similar to 

 macrolepidotum and pcecilura; it is said to be "much larger than in 



P. congestus") ALBIDUM, 11. 



aa. Species with the body elongate, little compressed, broad, the depth about 5 



in length, not very much greater than the thickness. 

 j. Head very short, roundish above, rather pointed forwards, 

 about 5 in length : cheeks subvertical : mouth rather large, 

 with thick lips, which are strongly plicate, the folds some- 

 what broken up : eye small : fins very small, the dorsal 

 rays 10 to 12 : scales rather large, 6-44 to 49-5 : color green- 

 ish-brown, a pale blotch on each scale, these forming con- 

 tinuous streaks along the rows of scales : back with more 

 or less distinct brownish cross-blotches ; fins brownish, not 

 much red ; the dorsal blackish at tip : size smallest : length 



less than afoot CERVINUM, 12. 



ft Lower lip thin, not infolded and "A-shaped "> forming a narrow, crescent-shaped 



border around the mandible. 



k. Head small, 5 times in leugth : muzzle prominent, but 

 less so than in M . coregonus : mouth moderate : back a 

 little elevated: depth about 3 in length : dorsal rays 12 

 to 14, its free border often incised : scales 6-45-5 : colora- 

 tion very pale ; lower fins white : size large ; reaches a 



weight of four pounds or more ALBUM, 13. 



kk. Head stout, as in M. velatum, rather long, 4 in length, 

 flattish above, muzzle truncate, not very prominent : 

 mouth moderate : back elevated : dorsal fin long, of 14 

 or 15 rays : sea-green above ; white below ; lower fins 



white THAT.ASSINUM, 14. 



ttt Lower lip infolded, /V-shaped when viewed from below, with a distinct median 



crease, in which the two halves of the lip meet, forming 



an acute angle : mouth smalL 



I. Dorsal large, with 16 (15 to 17) developed rays. 



m. Body stout, deep, compressed, the back elevated, the 



depth 3 to 4 in length : head short, heavy, flattish 



and broad above, thick through the cheeks, 3f to 4J 



in length : eye rather large, midway in head, 4 to 



5 in its length : muzzle rather prominent, blnntish, 



overhanging the very small mouth : fins very large : 



dorsal long and high, its height five-sixths the length 



of the head : pectorals nearly reaching ventrals 



color silvery, smoky above ; lower fins red : size 



large VELATUM, 15. 



