No. 500] 



SHORTER ARTICLES 



543 



a different distribution of the brachial syzygia ; we find, there- 

 fore, that the entire Pacific portion of the Polar-Pacific area, 

 from Bering Straits to the Antarctic Ocean, is really an exten- 

 sion of the latter division of the Polar-Pacific area northward; 

 so that, had we reasoned backwards from the facts at hand 

 before the appearance of Mr. Bather's paper, we might very well 

 have prophesied the discovery of a Ptilocrinus in the Antarctic 

 regions. 



Mr. Bather remarks that I did not publish a generic diagnosis 

 when I established Ptilocrinus: I did not, for the reason that 

 in a monotypic genus, we are quite unable to say which are 

 generic and which specific characters, and to tell in what way 

 a new species will differ from the type ; it is all right to indicate 

 the differences provisionally between a new monotypic genus 

 and older genera, but drawing up a diagnosis of a new mono- 

 typic genus implies rather more of a proprietorship over the 

 animal kingdom than I am willing to assume. 



Austin Hobart Clark. 



A NEW RHINOCEROS FROM THE LOWER MIOCENE 

 OF NEBRASKA 1 



Co., Nebraska, in the spring of UN)."), was a new form of hornless 

 rhinoceros. 



The type (No. HC105, collection of the writer) consists of a 

 complete skull, the posterior portion of the left jaw, the atlas 

 and the axis. This description has been delayed, hoping ad- 

 ditional materia] miizbt be secured. 



The specimen was found in an exposure of the Damionelix 

 Beds, about four miles west of the well-known Agate Spring 

 Fossil Quarry, on the ranch of James II. Cook. The boue horizon 



Beds are an integral part of the Lower Harrison Beds, forming 



