156 
MARINE SHELLS OF WEST COAST OF NORTH AMERICA 
below the middle; ventral margin evenly arcuate; surface sculptured by 
numerous fine, regular concentric incremental lines; neither lunule nor 
escutcheon, but a faint lunular circumscribing line in front of umbo; three 
prominent sharp, cardinal teeth in each valve, the anterior one being 
narrower and longer than the other two; external ligamental groove long, 
narrow; pallial sinus cuneiform, rather deep. Length, 43; height, 34; 
diameter, 26 mm. (Arnold.) 
Type locality, Puget Sound. 
Range. Sannakh Islands, Alaska, to Santa Barbara Islands and San 
Pedro, California. 
Genus PAPHIA Bolten, 1798. 
Shell trigonal, thick, compressed, closed; ligament internal, in a deep 
central pit; a minute anterior hinge tooth, and 1—1 lateral teeth in each 
valve; muscular scars deep; pallial sinus small. (Tryon. S. S. Conch.) 
Type. Paphia ala-papilionis Bolten, 1798. 
Distribution. West Indies, Mediterranean, Crimea, India, New 
Zealand, Chile, California. 
Range in Time. Miocene, Pleistocene. 
Subgenus Protothaca Dali, 1902. 
SECTION CALLITHACA Dali, 1902. 
Paphia tenerrima Carpenter, 1865. 
Plate 30, figs, la, lb. 
Proc. Zool. Soc. 1856, p. 200, Univ. Cal. Zool. Publ., 14; pi. 22. 
T. tenerrima, albido-fusca, obovali, compressa; marginibus aequaliter 
excurvatis; striulis radiantibus creberrimis, antice et postice fortioribus, 
et lirulis acutis concentricis, plus minusve dentantibus, eleganter ornata; 
lunula vix stria majore definita; intus, dent. card. iii. radiantibus, quorum 
valva in altera ii. altera i. bifidi sunt; sinu pallii maximo, elongato, 
lateribus suberectic, parum divergentibus, apice cicatr. ant. contiguo, 
subrotundato; margine vix crenulato. Long. 94; lat. 1.13; alt. 38. (Car¬ 
penter.) 
Type in Boston Soc. Type locality, Panama. 
Range. Puget Sound to San Quentin Bay, Lower California. 
Carpenter reports this from Panama, Coll. Col. Jewett. In the Pliocene at 
Santa Barbara and the Pleistocene at Santa Barbara, San Diego and 
Ventura, California. 
Paphia staminea Conrad, 1837. 
Plate 35, figs, la, lb. 
Jour. Acad. Nat. Sci. Phila., 7 :250; pi. 19, fig. 15. 
Shell suboval or suborbicular, convex, with numerous crowded radiat¬ 
ing striae, and finer concentric lines, most distinct on the anterior side; 
