Clark: The San Lorenzo Series of Middle California 153 



Conrad figured a very good specimen of a right valve. The 

 oblique shallow furrow referred to is on the anterior side of the 

 beaks instead of the posterior side; the posterior dorsal margin of 

 the left valve is not so strongly depressed as on the right valve and 

 the posterior end is more rounded. 



TELLINA PRAECUTA, n. sp. 

 Plate 12, figure 13 

 Type specimen 11166, Coll. Invert. Palae. Univ. Calif., loo. 14 



Shell elongate-ovate, strongly rostrate posteriorly ; beaks inconspicuous, anterior 

 to the middle of the shell, right valve rather strongly flexed near the posterior end. 

 Posterior dorsal margin long and straight ; anterior dorsal margin gently convex, 

 shorter than posterior margin; anterior end regularly rounded; posterior end nar- 

 row and truncated; ventral edge long and gently arcuate except near posterior 

 end where it is slightly concave due to the flexure of the valve. Surface sculptur- 

 ing not well preserved on specimens at hand but enough is seen to show that it 

 is of the same general type as T. tenuilineata and T. idea, having the same type 

 of depressed posterior margin. 



Dimensions. — Length, 36 mm. ; height, 19 mm. ; length of posterior dorsal edge, 

 21 mm.; length of anterior dorsal edge, about 15 mm. 



Occurrence. — University of California locality 14. 



At present the writer has only one specimen of a right valve of 

 this species, and that is a rather imperfect cast; fragments of other 

 specimens have been seen ; the form, however, appears to be so distinc- 

 tive in outline as to be worthy of description. 



TELLINA TENUILINEATA, n. sp. 

 Plate 10, figures 1, 3 and 5 

 Type specimen 11130, Coll. Invert. Palae. Univ. Calif., loc. 1131 

 Shell subovate in outline, inequivalve ; rostrate posteriorly with the posterior 

 end subtruncate ; beaks nearly straight ; valves slightly flexed to the right near 

 the posterior end; left valve slightly more convex than right; anterior end regu- 

 larly rounded; ventral edge regularly convex except near the posterior end, 

 where it is slightly concave due to the flexure of the valves. Escutcheon well- 

 defined, elongate, narrow and strongly depressed, wider on the left valve, the 

 wider part being near the middle of the posterior dorsal margin. Ligamental 

 groove deep, shorter than the escutcheon. Lunule small and deeply inset. Sur- 

 face of right valve covered by fairly fine, regularly spaced, sharp, concentric, 

 raised lines, which are closely crowded together near the beaks, the interspaces 

 becoming wider and more regular toward the ventral edge ; on the depressed 

 posterior margin these lines are rather strongly imbricated. A fairly broad, 

 shallow flexure sinus near the posterior dorsal edge, posterior to which the dorsal 

 margin is depressed, the depressed area being separated from the mam surface 

 of the shell by a distinct ridge ; on the depressed area, posterior to this ridge and 

 extending from near the beak to the posterior end, is a fairly deep sinus. Left 



