98 CALIFORNIA ACADEMY OF SCIENCES. 



Distinguishable from L. ttvphria by smaller size, truncated posterior end with 

 process on interior at this end, comparatively coarser sculpture, straighter posterior 

 dorsal margin, and fewer teeth. The type shows two concentric furrows, one at 2.5 

 mm. and the other at 4 mm. from the umbo, which are probably the result of inter- 

 rupted growth. Specimens identified by Dr. Dall, who pronounced them a variety of 

 Z. minuta Fabr., a northern species. 



Rare in lower San Pedro series of Deadman Island and San Pedro. The 

 specimen figured is the type, which is from the lower San Pedro series at Deadman 

 Island, and is now in the United States National Museum. 



Pleistocene. — San Pedro (Arnold). 



i6. Leda taphria Dull. 



Plate XVII, Fig. 5. 



Leda taphria Dall, Nat. Hist. Soc. British Columbia, Bull. No. 2, 1897, p. 7, PI. II, figs. 6 and 8 

 {^ccrlata Hds., 1844, not Conr., \%-i,2\ fide Dall, Trans. Wagner Inst. Sci., Vol. Ill, 1898, 



P- 579)- 



Nucjila ctzlaia Hds., Proc. Zool. Soc, 1844, P- 99! Zool. Sulph., p. 64, PI. XVIII, fig. 13, 1844. 



Leda ccelata Hds., Thes. Conch., Vol. Ill, No. 42, figs. 95, 96. Carpenter, Brit. Assn. Rept., 1863, 

 p. 644. Gabb, Pal. Cal., Vol. II, 1869, p. 103. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, 

 p. 245. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 192. 



Shell small, trigonal, oblong and rounded in front, produced and pointed behind; surface 

 sculptured by numerous sharp, concentric, raised lines; umbones central, turned toward posterior 

 end; escutcheon long, narrow and concentrically striated ; hinge with prominent internal cartilage-pit, 

 and about twenty sharp teeth on each side; pallial line with a small sinus; umbonal area with a linear 

 impression joining the anterior adductor. 



Dimensions.— \^ong. 19 mm.; alt. 11 mm.; diam. 8 mm. 



This is the largest of this genus found in these deposits, and is easily recog- 

 nized by its size, sculpture and peculiar teeth. Hinds' name, L. cuJata, was preoccu- 

 pied by a species of Conrad's, and Dall has renamed Hinds' species for that reason. 

 Specimens identified by Dr. Dall. 



Found in Pliocene of Deadman Island and Timm's Point; lower San 

 Pedro series of Deadman Island and San Pedro; and in the upper San Pedro series 

 of Deadman Island, San Pedro, Crawfi,sh George's, Los Cerritos, and Long Beach. 

 Found also in the Pliocene of Pacific Beach, and in the Pleistocene of Spanish Bight 

 and Pacific Beach, San Diego. The specimen figured is from the lower San Pedro 

 series at Deadman Island, and is now in the collection of Delos Arnold. 



Living. — Bodega Bay to San Diego (Cooper). 



Pleistocene. — Santa Barbara to San Diego (Cooper) : San Pedro; San Diego 

 (Arnold). 



Pliocene. — San Fernando; San Diego well (Cooper): San Pedro; San Diego 

 (Arnold). 



