1912] Miller: Pacific Coast Avian Palaeontology 69 
sected by river canons. The indications are that the actual 
elevation at present is considerably greater than that during the 
deposition of the bone-bearing material. Certainly the relation 
of the cave to the river level has changed in the neighborhood of 
eight hundred feet. There is no evidence of a later subsidence 
noted, so we may assume that the conditions during the period 
of deposition were more like those at Rancho La Brea than they 
are at present, 1e., less abrupt elevation and a smoother top- 
ography. The presence of Dendragapus in the cave deposits is 
an indication, however, that conditions were not identical in 
the two localities. 
A very interesting description of the various chambers and 
galleries of the cavern is given in Sinelair’s paper. The fossil- 
bearing matrix represents the accumulation on the floors of the 
chambers and pockets in the form of fans of detritus, admitted 
doubtless through old chimney-like chutes now entirely blocked 
by limestone accretions and washed debris. These fans of ac- 
cumulated material were enerusted, and in some _ instances 
cemented, by stalagmitiec deposits so that blasting had to be re- 
sorted to in places. 
The remains are in most cases entirely dissociated. Sinclair 
notes the finding of a few skeletons in their proper anatomical 
relations, such as those of a squirrel, a woodrat, a snake, and a 
bat. These are all animals which would go into eaves of their 
own accord and after death fall upon the floors of the caverns. 
No ease of bird skeletons in any degree associated is to be found. 
The bones have entirely lost their organic matter and appear 
almost as though caleined. Perfect bones of the smaller verte- 
brates are rare. In most cases fracture has occurred and in 
many the articular surfaces have been injured, either on account 
of the delicacy of the cancellated bone in that region, or because 
the presence of articular cartilages tempted the appetites of 
enawing forms. Weathering and cracking due to exposure on 
the surface is the only reasonable explanation of the imperfee- 
tions of some specimens. 
Sinelair suggests three methods of possible introduction of 
animal remains into the cave. Washing by rills which carried 
bones from the surface down by way of the nearly vertical chim- 
