12 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 



Finally, as to the aggregation and development of Bacteria abont 

 living Infusorians, tliis I have noticed in a colorless marine species, viz, 

 Zoothamnium alternans, and the same fact has been observed by Stein. 

 Both Stein and myself have noticed Bacilli mostly in this relation to 

 other living colorless Infusorians, but in the case of dead and colorless 

 Infusorians the remains of the animals are usually attacked at one side 

 and gradually invaded by Bacilli and Micrococci, and altogether inde- 

 pendently of any peculiarly local oxygen-yielding source in the vicinity. 



In conclusion it may be said that if there exist green VorticcUw 

 ■^hicli have the green coloring matter arranged diffusely in the ecto- 

 plasm in one species, and in another confined to distinct granules as 

 observed in the species here described, it is fair to presume that, as in 

 the cases of the three species of iStentor alluded to above, that we also 

 have to do here with two very distinct species of Bell-animalcules. It 

 is also fair to assume that if the different species present their coloring 

 matters in diverse conditions and modes of arrangement that such mat- 

 ters may have correspondingly different functions, and that it does not 

 necessarily follow that the green granules even are a sure indication of 

 the presence of true chlorox^hyll, though it may simulate that of the 

 plant in its relation to the stratum of plasma covering the cell-wall. 

 Why not suppose that some of these coloring matters of Infusorians 

 have a function similar to haemoglobin? It would, however, be much 

 easier to suppose that the quasi-chlorophyll grains of V. chlorosUfjma 

 were truly of the nature of chlorophyll than to assume as much regard- 

 ing the diffuse green color as observed in the ectoplasm of a supposed 

 variety or closely affiliated species of V. campamila, as has been done by 

 Eugelmann. 



Washington, Decemher 20, 1883. 



A NEW GEOGRAPHICAL RACE OF THE MOUNTAIN SHEEP (OVIS 

 MONTANA DALLI var. nov.) FROM ALASKA. 



By E. W. :VE:L,S0N. 



During the course of my residence at Saint Michael's, Alaska, and sub- 

 sequent travel along the Arctic coast of this Territory, between July, 

 1877, and September, 1881, hundreds of skins were seen of the Mountain 

 Sheep, which I here designate as a new geographical race. 



The types of the new race are two specimens brought me by Mr. L. 

 ^N". McQuesten, a fur-trader living at Fort Eeliance, on the Upper Yukon 

 Biver, near the point where it crosses the British boundary line. These 

 specimens were killed by the Indians on some mountains south of Fort 

 Yukon, and on the west bank of the river. 



From Mr. McQuesten, and various other fur traders along the Yukon 

 and elsewhere, and my own observations, I learned that the range of 



