1887.] NATURAL SCIENCES OF PHILADELPHIA. 313 



Hydra fusca ? The browu hydra. Animal more robust than 

 the former, of the same shape ami number of arms, but with tlie 

 body less attenuated when extended and with the arms habitually 

 longer in proportion to the body, but capable of extension to six 

 times the length of the latter. Color usually pale brownish or red- 

 dish ; sometimes deeper, sometimes paler. In ponds and common 

 on the under side of stones in the Schuylkill and Delaware Rivers, 

 in the vicinity of Philadelphia. Not observed in the sexually ma- 

 ture condition. The color of the aninuil in a measure appears to 

 depend on the nature of the food ; and it may become a bright red, 

 of variable tint, by feeding on similar colored entomostraca or in- 

 sect larva (See Proc. 1880, 156.) From pi'olonged abstinence the 

 color fades and the animal becomes almost white. 



Craig D. Ritchie was elected a member. 



The following were ordered to be published : 



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