UMBBIDiE. 53 



The species of this family now known are the following, beginning 

 with the form least specialized : — 



1. Asternotremia isolepis Xelson.— Illinois, both in tributaries of Lake 

 Michigan and of the Ohio and Mississippi. 



2. Asternotremia mesotrema Jordan. — Georgia to Arkansas. 



3. ApJiododerus coo/aa>ms Jordan.— Wabash Valley ; at various points 

 both in Indiana and Illinois. Many specimens in United States National 

 Museum. 



4. Apliododerus sayamis (Gilliams) De Kay.— Streams coastwise, New 

 York, New Jersey, south to Louisiana. 



UMBEIDJE 



38. UMBRA PYGM^A, [De Kay) Bean, MSS. 



Leudscus pygmceiis, De Kay, Fishes N. Y. 214.— Stoker, Synopsis, 414. 



Melanura pi/rjmcea, Baird, Ninth Smithsonian Eept. 1855. 

 Fundulus fiiscns, Ayres, Bost. Journ. Nat. Hist, iv, 296. — Stoker, 1. c. 431. 

 Umbra or Melanura Umi, part, various authors (all quotations from Southern New 

 York and streams of the Atlantic coast). 



My friend Dr. T. 11. Bean, of the Smithsonian Institution, calls my 

 attention to the fact that the Mud Minnow of our eastern streams is 

 quite a different species from the Umbra or Melanura Umi, with which 

 it has thus far been confounded by all writers who were aware of the 

 relations of the fish. The syuonj-my of M. pygmwa is given above. 

 Its characters are as follows : — 



Head about 4 in length ; depth 4.^ ; body more terete and less com- 

 pressed than in ill. Umi; head broader, less depressed, with larger eye ; 

 interorbital space more convex ; snout shorter, profile more gibbous. 

 Dorsal 13 ; anal 7 (dorsal 14, anal 8 in M. Umi). Lateral line 35. 



Coloration : — dark brown, a series of whitish lengthwise stripes along 

 the rows of scales ; a black bar at base of caudal ; no traces of verti- 

 cal bars; blackish bands forward, downward, and backward from eye; 

 a dark vertebral band. M. Umi is more mottled, not striped, and always 

 shows pale vertical cross-bars. Specimens examined from Tarboro', 

 N. G., and from points in New Jersey and Kew York. The smaller 

 number of brauchiostegals (four instead of five or six) is the only char- 

 acter known to separate^ Melanura from Umbra. 



