THE ENCHYTRAEIDAE (OLIGOCHAETA) COLLECTED . BY THE 

 CANADIAN ARCTIC EXPEDITION OF 1913-191G. 



PAUL S. WELCH. 



(Abstract.) 



The collections of Enchytraeidae made by the Canadian Arctic Expedi- 

 tion (Southern Division) of 1913-1916 constitute the first records of these 

 annelids in the vast territory lying between Greenland and Bering Strait. 

 They were sent to the writer for identification and found to contain seven 

 species representing four genera, together with four groups of sexually imma- 

 ture specimens representing two genera. With the exception of two new 

 species, all have been recorded from arctic Eurasia. An interesting similarity 

 of the arctic enchytraeid fauna of North America and Eurasia is thereby 

 indicated. 



SOME OBSERVATIONS ON THE LONGITUDINAL FISSION OF THE 



TENTACLES OF HYDRA FUSCA. 



A. M. CHICKERING. 



(Abstract.) 



The observations recorded in this paper show that longitudinal fission as 

 well as budding may increase the number of tentacles in Hydra fusca ; that 

 longitudinal fission of a tentacle may result in producing two new tentacles 

 equal in size and otherwise normal or it may produce two of iinequal size 

 and abnormal position ; that longitudinal fission usually occurs from the distal 

 toward the proximal end but may proceed in the opposite direction ; that 

 along with the process of longitudinal fission there occurs a rapid degenera- 

 tion process resulting in the elimination of some of the tentacles ; and that 

 the processes described seem to be associated in some manner with a dis- 

 eased condition of the animals. 



NOTES ON A SPECIMEN OF STYLEMEY8 NEBRAGENSIS. 



E. C. CA.SE. 



(Abstract.) 

 A specimen of this turtle discovered by the University of Michigan expe- 

 dition in the Big Bad Lands of South Dakota is in such a singularly good 

 state of preservation that it permitted the .shell being removed from the 

 matrix and mounted as a recent specimen would be. This has resulted in 



