42 IOWA ACADEMY OF SCIENCES. 



movement of the northern and western species toward the south and east. 

 Almost without exception the novelties included in the above list come from 

 the north and west. 



Among mammals the same is true, although the evidence is not so exten- 

 sive. The Prairie Hare is the most marked case in point. 



REPTILES. 



The following species are not found in Prof. Osborn's catalogue. Speci- 

 mens of each are in the University museum. 



OPHIDIA. 



Eutainia satirita (L.). Johnson county, Iowa. 

 Coluber guttaius, L. Rippey, Iowa. B. F. Osborn. 

 Biadophis punctaius (L). Rippey, Iowa. B. F. Osborn. 

 Crotalus horridus, L. Iowa City, Iowa. 



LACERTILIA. 



Eumeces septentrionalis (Baird). 



BATRACHIA. 



Amblystoma jeffersonianum (Green), Baird. Specimens from Iowa in 

 University museum. 



FISHES. 



The following species should be added to the list on the basis of specimens 

 from Iowa in the University museum. 

 Ammoccetes niger (Raf.). Jordan. Iowa City. 

 [Moxostoma microlepidota^ (LeS.), Jordan. Iowa City.] 

 Gliola forbesii, Jordan.- Iowa City. 

 Acantharchus pomotis (Baird), Gill. Iowa City. 



SIGNIFICANCE OF THE CONCEALED CRESTS OF FLY-CATCHERS. 



BY C. C. NUTTING. 



In all the works on animal coloration that have come under my observation, 

 there is a marked absence of any attempt to account for the concealed crests of 

 bright colors on the crown of many bird'j, notably the Ti/rannidce or "Fly-Catchers." 



The writer, although the first, so far as he knows, to offer an explanation for 

 this class of facts, was for a long time compelled by press of other duties, to defer 

 for a number of years any considerable investigation in this direction. Last sum- 

 mer, however, he took the time to examine the collection of Tfimnnidce at the 

 Smithsonian Institution, probably the largest series of this exclusively new world 

 group in the world.^ 



iThls is doubtless the same species that is entered by Meek in Osborn's list as 3f. 

 duquesnii, and is therefore not a species new to the State. 



2Synopsis of Fishes of North America. .Jordan and Gilbert. 1882, p. 174. 



3 The writer wishes to take this opportunity to acknowledge the never failing court- 

 esy and patience of Mr, Robert Ridgway in facilitating the e.xamination of the splen 

 did collection under his charge. 



