162 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Se». 



The most important species thus far known are: Cardium 

 lorenzoanum Am., Crenella porterensis Weaver, Dosinia 

 inatheii'soni Gabb, Macrocallista matheivsoni Gabb, Macrocal- 

 lista vespertina Con., Macoma nasuta Con., Marcia oregonensis 

 Con., Mytilus mathcwsoni Gabb, Mytihis ynesianus Arn., 

 Nucula gettysbiirgensis Rgn., Niicida tozvnsendi Dall, Panopea 

 generosa Gld., Pecten hranneri Arn., P eaten zvaylandi Arn., 

 Phacoides acutilineatus Con., Solemya ventricosa Con., Spisula 

 albaria Con., Tellina lorcnzoensis Arn., Thracia trapczoidea 

 Con., Thyasira bisecta Con., Yoldia impressa Con., Yoldia 

 oregona Shum., Agasoma gravidum Gabb, Crepidula prcurnpta 

 Con., EudoHum petrosum Con., Fusiis hecoxi Arn., Miopleio- 

 nia indurata Con., Molopophonis gabbi Dall, Strepsidura 

 oregonensis Dall, Turcicida washingtoniana Dall, Turritella 

 newcombei Merriam, Turritella oregonensis Con., Aturia 

 angustata Con. 



These forms indicate tropical or subtropical waters, which 

 extended up at least as far north as Puget Sound. Note- 

 worthy is the appearance of the first Recent species: Panopea 

 generosa Gld., Macoma nasuta Con., Thracia trapezoidea, and 

 Thyasira bisecta Con. The others are all extinct, but many 

 have living relatives in warm latitudes, especially Aturia and 

 Eudolium. There are no apparent relations with the Caribbean 

 Oligocene, the Panama portal having probably been closed at 

 this time. An immigration from the Orient is shown by the 

 presence of Dolium, Voluta (Miopleionia), and other forms 

 with near relatives still living in that region. 



EOCENE. 



Tejon. The upper Eocene, Tejon, fauna of California has 

 recently been described in monographic form by R. E. Dicker- 

 son,*" so that it is unnecessary to give further references. This 

 same fauna extended unchanged to Puget Sound, and Veneri- 

 cardia planicosta, the "finger-post of the Eocene", reached up 

 to Alaska.*^ 



The most characteristic species of this horizon are : Balano- 

 phyllia striata Gabb, Flabelluin remondianum Gabb, Trocho- 



*" Stratigraphy and fauna of the Tejon Eocene of California Univ. of Calif. Pub. 

 Bull.. Dept. of Geol. vol. 9, No. 17, (1916), pp. 363-524. 



*' W. H. Dall, Harriman Alaska Exped. Neozoic Invert, fossils, p. 103. 



