OF THE ANIMALCULES OF THK RED SNOW. 83 



converted into a carapace. It is at this point only that the motions of the 

 animal become visible. I had the good fortune to observe, and to be 

 able to make drawings of the various grades of this mode of reproduc- 

 tion, and I am convinced that this animal, far from belonging to the 

 genus Gyges, on the contrary, ought not only to be looked upon as the 

 type of a new genus, but still further, to constitute a family, on account 

 of its very peculiar mode of reproduction and development. 



3. I place in the genus Gyges of Ehrenberg another infusoria, of an 

 equally remarkable form, which does not appear to have been observed 

 by Mr. Shuttleworth. In the red snow may be occasionally seen 

 globular organisms, containing in their interior from two to five indivi- 

 duals, enclosed in a carapace apparently of a vitreous character. The 

 colour of these animals, thus living in the same case, is of a dark red ; 

 they frequently adhere one to the other, and arrange themselves in the 

 form of a cross ; they are also frequently separate. The small indivi- 

 duals, probably the young, were of a clear yellow hue ; I could not ob- 

 serve the slightest motion in them. 



4. An infusoria of the family of Bacillaria. It is very abundant in 

 the red snow, and is the smallest of all the kinds I have met with. We 

 frequently saw two of them adhering together, and ready to separate. 

 Their colour is yellowish brown. With the exception of a few bright 

 spots in their interior, I could not distinguish their structure, neither 

 could I detect the slightest motion. 



5. A species of Aretiscon, having two hooks to the feet. This ani- 

 mal, known under the name of Macrobiotus, has usually the intestine 

 filled with several organisms met with in the red snow, and is that 

 which gives it a red hue, whilst its natural colour is a light brown. 



6. The most interesting animal of the red snow is a Rotifer, a variety 

 of Philodina roseola Ehr. We met with it abundantly in the snow of 

 the lower glacier.of the Aar. Having remarked that the ovary was of 

 a much deeper colour than the other parts of the body, I directed my 

 attention especially to this organ, and I was not long before I perceived 

 eggs in different periods of development. The young eggs were per- 

 fectly round, and of a deep red hue, absolutely similar to the globules of 

 Protococcus, described and figured by Shuttleworth, in his fig. 2. I also 

 found eggs with a thin transparent covering, furnished on all sides with 

 small pointed projections. After a time others were also observed, of a 

 larger size, but similar in form to those figured by Ehrenberg, and ready 

 to be deposited. The great similarity of the immature eggs with the 

 globules of Protococcus figured by Shuttleworth, attracted our atten- 

 tion, so much so, that at the moment the idea suggested itself, that these 



G 2 



