106 ALASKA GEOLOGY 



Ostrea sp. 



Localities. Upper beds, 3373; lower beds, 3377. 



A large species in imperfect condition but resembling closely O. 

 idriaensis Gabb, from the Tejon Eocene of California. Specimens 

 reach a length of 80, and a breadth of 55 mm., and are frequently 

 perforated by the Ctiona alaskana. 



Pecten (Chlamys) sp. 



Locality. Upper beds, 3373. 



Fragments of the upper valve of a Pecten of the type of P. is- 

 landicus Mu'ller having nineteen ribs on the disk and six on the poste- 

 rior auricle, with traces of a fine reticulate surface sculpture, were 

 obtained by Dr. Palache. The height of the valve would be about 

 40 mm. and the proportions about those of P. islandicus. 



Modiolus harrimani sp. nov. 

 pi. ix, fig. 7. 



Localities. Upper beds, 3373 ; lower beds, 3378, very abundant 

 but crushed. 



Shell small, short, broad, with nearly terminal beaks ; anterior end 

 narrow, rounded, blunt ; posterior end broad, compressed, subtrun- 

 cate ; base nearly straight, with the valve above it and below the 

 median convexity somewhat impressed. Length 19, maximum width 

 12.5, diameter about 6 mm. 



This curiously wedge-shaped little Modiolus is concentrically stri- 

 ated. It is very abundant but always distorted in the lower beds ; a 

 single valve in normal condition was found in the upper beds. 



Modiolus sp. 



Locality. Lower beds, 3377. 



A fragment of a large rounded quadrate species recalling the recent 

 M. vulgaris was collected. It is rather strongly concentrically sculp- 

 tured. 



Modiolus alaskanus sp. nov. 



pi. x, fig. 3. 



Locality. Upper beds, 3373. 



Shell small, rounded quadrate, finely concentrically striated, moder- 

 ately convex ; anterior end with the beaks adjacent, rounded ; base 

 nearly straight ; posterior end wider, rounded, obliquely subtruncate ; 

 ventral third with the usual constriction. Length 17, maximum width 

 9, diameter about 4 mm. 



