74 University of California Publications in Geology [Vol.7 



formation of the cave is essentially the same except that the 

 work of solution is still probably going on to some extent. The 

 method of entombment of the organic remains appeared to Fur- 

 long to be the same as that acting in the case of Potter Creek 

 Cave, i.e., the washing in of surface material by the action of 

 streamlets. 



The presence of Megalonyx and Equus indicate the Pleisto- 

 cene age of the bone-bearing deposits in the fissure. There ap- 

 pear no remains of the large ungulates Euceratherium and 

 Preptoceras to correspond with the deposits of the Shasta caves, 

 but this condition may be more apparent than real, since but 

 a limited amount of work was done in the cave before the level 

 of the water in some of the passages rose to a point so high that 

 access to the main bone-bearing chambers was prevented. 



But twelve species of birds are represented in the collections 

 from this cave. Four of these are no longer represented in the 

 region. The fact that the cave is still open and that changes due 

 to the action of water are still going on lends a feeling of uncer- 

 tainty as to the exact age of any specimen. The association in 

 loose material of remains which are unquestionably Pleistocene 

 in origin with others representing still existing species is no 

 guaranty of the age of the latter. There is continually going 

 on a measure of differential motion in some of the debris ac- 

 cumulated, which would possibly mingle fragments deposited 

 at quite different times. Solution, shifting and re-cementing 

 may have recurred several times although the excellent state of 

 preservation of most of the bones would militate against the idea 

 that a great deal of such movement had taken place. 



The few mammals thus far identified from Hawver Cave are 

 listed as follows : 



Equus occidentalis ( ?) Leicly. 

 Aplodontia, sp. 



Megalonyx, sp. 



Felis hippolestes Merriam, C. H. 



