104 American Seashells 



I % inch in maximum diameter, elliptical in outline, generally with a low 

 apex which is placed % back from the front end. The 15 to 25 strong, coarse 

 radiating ribs give the edge of the shell a strong crenulation. Color dirty 

 gray-green. Underside of shell whitish, irregularly stained in the center with 

 blackish brown. Edge of shell between the serrations is stained blackish to 

 purplish brown. A common species found clinging to rocks high above the 

 water line but within reach of the ocean spray. A. spectrum Nuttall is the 

 same species. Do not confuse with the smaller A. conus which is evenly 

 glossed, instead of coarse and dull, on its interior center. 



Acmaea testudinalts scutum Eschscholtz Pacific Plate Limpet 



Alaska to Oregon (common) to Lower CaHfornia (rare). 



I to 2 inches in maximum diameter, almost round in outline, quite flat, 

 with the apex toward the center of the shell. Smoothish, except for very fine 

 radial riblets in young specimens. External color greenish gray with slate-gray 

 radial bands or mottlings. Interior bluish white with faint or darkish brown 

 spot. Inner edge with band of alternating bars of black or brown and bluish 

 white. The name of this species was also known as tessulata Miiller. The 

 typical testudmalis from the Arctic Seas and New England rarely, if ever, 

 exceeds a size of i K- inches, is not so round, and has a darker, more con- 

 centrated brown patch on the inside. Intergrades exist in Alaskan waters. 

 The Pacific race was also named patina Esch. 



Acmaea asfin Middendorff Black Limpet 



Alaska to Mexico, clinging to the gastropod, Tegula. 



/4 inch in maximum diameter, high-conic, elliptical in outline, and solid 

 black inside and out. In the northern part of its range, the Black Limpet is 

 found living attached to the common snail, Tegula funebralis A. Adams, 



Acmaea triangularis Carpenter Triangular Limpet 



Southern California to Gulf of California. 



Yi inch in maximum diameter, oblong in outline, side view distinctly 

 triangular. Color whitish with 3 or 4 vertical, rather broad, brown stripes on 

 each side. Found among coralline algae from the shore line down to several 

 fathoms. Uncommon. 



Acmaea depicta Hinds Painted Limpet 



Santa Barbara, California, to Lower California. 



