184 Kansas Academy of Science. 



14. Saxidomus gibbosus Gabb. Plate II, fig. 14. 

 Saxidomus gibbosus Gabb, Pal. Cal., vol. II, p. 58, pi. 16, fig. ISa-b, 1869. 



Description from cast: Shell subquadrate, very inequilateral; 

 beaks anterior, nearly terminal; anterior end excavated above, nar- 

 rowly rounded below; posterior end convexedly subtruncated, some- 

 times, too, a little obliquely truncated; base broadly rounded; cardinal 

 margin gently sloping and slightly convex; a few fragments of the 

 shell show faint lines of growth; inside of shell not seen. 



The specimen figured was the only one obtained. It is from the 

 lower shales at East Clallam. 



Pliocene: Eagle Prairie, Humboldt county, California (Gabb). 



Oligocene-Miocene: East Clallam, Wash. (Reagan). 



Superfamily Tellinacea; Family XXX Tellinid^. 

 Genus Tellina Linne. 



Shell more or less elongated; rostrum more or less twisted; two 

 lateral teeth in each valve. 



15. Tellina albaria (Conrad). Plate II, fig. 15. 

 Tellina albaria Con., Wilkes's Expl. Exped., vol. X, p. 725, pi. 18, fig. 5. 



Shell small, more or less compressed, thin, subtriangular; beaks 

 submedial; anterior extremity obtusely rounded to angulate; pos- 

 terior end regularly rounded; ventral margin straight at middle; 

 surface practically smooth in young specimens but marked with 

 concentric lines of growth in the older specimens, somewhat 

 strongly in the very old; the shells become more gibbous with age. 



Dimensions of a young specimen : Lat., 24; alt., 16; diam., 5. Di- 

 mensions of an adult specimen — the specimen figured: Lat., 31-. 

 alt., 22; diam., 13. 



This species is very common in the Gettysburg shales, also in 

 the sandstone of the upper series at Gettysburg. 



Miocene: Astoria, Ore. (Conrad). 

 . Oligocene-Miocene: Gettysburg, Wash. (Reagan). 



16. Tellina arctata Conrad. Plate II, fig. 16a, 166. 



Tellina arctata Con., Wilkes's Expl. Exped., vol. X, p. 725, pi. 18, fig. 3; 

 equals Macoma arctata Con., Gabb, Pal. Cal., vol. II, 1869. 



Shell subelliptical, oblong, compressed; anterior extremity trun- 

 cate and slightly sinuous, reflected below ; basal margin elliptical 

 to arcuate ; ligamental margin declining ; posterior margin rounded; 

 surface marked by very faint, closely and regularly arranged con- 

 centric lines, most of which are obsolete on the worn specimens at 

 hand; beaks small, pointed, and placed nearest the anterior ex- 

 tremity ; interior of valve not seen. 



