THE FISHES OF ALASKA. 271 



50. Diaphus theta Eigenmann & Eigenmann. 



One specimen 2.5 inches long dredged at station 4267, off Mount Edgecumbe in 922 fathoms. 

 Head 3; depth 4.5; eye 3; snout about :! in eye; dorsal 12; anal 9; pectorals 12; lateral line 35. 



Family in. CHAULIODONTIDjE. 



51. Cyclothone microdon iCiiinther). 



Recorded l>y (iilliert ls05i from Albatross Btations 3307 and 3308 in Bering Sea. Not taken by us. 



52. Chauiiodus macouni Bean. 



One specimen 4.25 inches long from station 12:', 1. lielnn i anal near I.nring, and another 3.5 inches 

 long from station4 257, in Lynn (anal. Also recorded from station 3340, south of Alaska peninsula 

 (Gilbert 1895 



Family ro. PLAGYODONTIDvE. 



53. Plagyodus eesculapius Bean. 



Originally described by liean (1884) from Iliuliuk, (Jnalaska. Recorded also from Summer 

 Harbor, [Jnalaska (Jordan & Gilbert 1899). 



k> 



Fig.'" i lugyn.lus irsculiipius Ili'im. 

 54. Plagyodus borealis i <iill). 

 Recorded from Captains Harbor, [Jnalaska (Bean 1882). 



Family 20. N0TACANTHID£. 

 55. Macdonaldia challengeri iVaillant I, 

 Recorded by Gilbert L895) from Albatross station 3308 in Bering Sea. 



Family 21. DALLIID/E. 

 56. Dallia pectoralis Bean. 



This interesting fish, which is the sole representative of a family and order of fishes, was first 

 described by Bean (1880), from specimens collected by its discoverer, Dr. Dall, at St. Michael. 

 Specimens were also reported by Nelson > 1887) from Andreafski, Yukon River, and mouth of Tanana 

 River, and by Gilbert 1895) from Nushagak River. It occurs in great numbers on St. Lawrence 

 Island. We have but a single specimen, one secured by Gilbert. Although so abundant in Alaska, 

 this species is rare in museums and collections in general, illustrating the well-known fact that the 

 commonest forms in nature are often the rarest as preserved specimens Turner 1 1886) says: 



This species is probably the most abundant of all the fishes which occur in the fresh and brackish 

 waters of the northern part of Alaska. It is found in all the small streams of the low grounds, in the 



