272 Fresh Water Aquarium 



or white color gradually changes to a dark 

 silver gray. Mr. Eggeling's experiences 

 with the Olm as an aquarium inmate are 

 satisfactory in every respect. 



The Mud-puppy, or Water-dog (Necturus 

 maculatus) , is found in the region of the 

 Great Lakes and in the Eastern States. 

 It is nearly related to the Olm and is dark 

 brown above, mottled with lighter blotches 

 of irregular shape and different size. The 

 belly is yellowish-white or light brown and 

 shows some roundish dark spots. Fully 

 grown it is often from 20 to 24 inches 

 long. The body is very soft but not un- 

 graceful in form. The head is broad 

 and clearly separated from the body by a 

 slender neck. The eyes are very small and 

 not nearly as prominent as in many other 

 salamanders. On each side of the head 

 there are three gills which are of feathery 

 appearance and a rich velvety purple 

 color. The Mud-puppy is somewhat noc- 

 turnal in its habits, being very lively and 



