216 PALAEONTOLOGY OF CALIFOKNIA. 



BARBATIA, Gray. 



B. Morsei, n. s. 



PI. 32, Pig. 286. 



Shell small, thin, subcompressed, oblique, broadest posteri- 

 orly ; beaks small, approximate, anterior; area long and very 

 narrow, shorter than the shell; anterior end short and broad; 

 posterior end oblique above, rounded below; base sinuous, 

 slightly gaping. Surface depressed in the middle and towards 

 the ends, ornamented by numerous fine radiating ribs, alternat- 

 ing pretty regularly in size in the middle of the shell. Hinge 

 slender, composed of numerous small, oblique teeth. 



Figure, natural size. 



Locality: San Diego ; collected by Mr. Morse. 



YOLDIA, Moller. 



Y. NASUTA, n. s. 

 PI. 32, Fig. 287. 



Shell thin, convex, elongate ; beaks subcentral, a little pos- 

 terior; cardinal margin concave in advance, sinking convexly 

 behind ; anterior end produced, most prominent above. Hinge 

 composed of uniform teeth, largest in advance of the beaks. 

 Surface polished. 



Figure, natural size. 



Locality : A single specimen in the collection of the California Academy of 

 Natural Sciences, labelled "Los Angeles," and associated with Cretaceous fos- 

 sils. This shell may be Cretaceous, or possibly Tertiary. The discovery of better 

 authenticated specimens will be necessary to determine its true age. 



