Geological Papers. 205 



By comparing the above lists it is found that only five species 

 are common to both formations. It is also found by comparing 

 the Quillayute list with lists of living species that about two-thirds 

 of the species given in it are living at the present time, six of 

 which are now living in Quillayute Bay adjacent/'^ The fossils 

 that are supposed to be extinct are followed by a *. 



The species in the Quillayute list above that are preceded by a 

 * have been described in the Oligocene-Miocene fossils, to which 

 the reader is referred for a description of each. The other Quil- 

 layute fossils are described below. 



The species preceded by (P) are also found in Purisima-San 

 Diego ( Lower Pliocene) formation of California, and those marked 

 (M) are found in the Merced-Deadman Island (Upper Pliocene) 

 of the same state. It is thus seen that sixteen fossils from the 

 Pnrisima-San Diego formation, two doubtfully so classed, and sev- 

 enteen from the Merced-Deadman Island formation are found in 

 the Quillayute formation."'''' Also, by comparing Doctor Arnold's 

 Pleistocene lists with the lists from this formation, it is found that 

 twenty of the fossils are common.'^*^ The percentage, therefore, 

 seems to favor an Upper Pliocene for the age of the Quillayute 

 formation. And again, a like percentage of the fossils are repre- 

 sented in the Miocene, Consequently, this would seem to place 

 the formation at the base of the Pliocene. Following is a descrip- 

 tion of the fossils: 



ECHINODERMATA. 



Class II EcHiNomEA; Sub-branch III Euechinoidea. 

 Order IV Clypeastroida; Family 3 Scutellid^; Genus Scutella Lam. 



Scutella sp. 

 The inside cast of a specimen of this genus was found in the 

 Quillayute formation at the abandoned mouth of Maxfield creek, 

 near Quillayute, Wash. 



MOLLUSCA. 



Class Pelecypoda; Order Prionodesmacea. 



Superfamily Nuculacea; Family VI Ledid.e; Genus Yoldia Moller. 



Shell oblong, slightly attenuated behind; compressed, gaping, 

 smooth or obliquely sculptured with a dark-olive, shining epider- 

 mis; external ligament slight; hinge as in Nucida and Leda; pal- 

 lial sinus deep. (After Arnold.) 



54. See Reagan, "Some Sea Shells from La Push, Wash." Trans. Kan. Acad. Sci„ vol. XXI, 

 part I, 1907, pp. 168-177. 



55. See Professional Paper No. 47, pp. 28-32. 



56. Loc. cit., pp. 33-37. 



