LITTORINA.— Plate XVIII. 



rarius obsolete rufo-pmictatd, transveisim profundi 

 sulcata; anfractibus convexiusculis ; aperturd semi- 

 orbicularis columella latissimi excavato-depressd, au- 

 ranlio-fmcd, supertie purpureo-maculaid. 

 The modest Littorina. Shell ovately oblong, whitish, 

 rarely obsoletely dotted with red, transversely deeply 

 grooved ; whorls rather convex ; aperture semiorbi- 

 cular, columella very broadly excavately depressed, 



orange-brown, blotched with purple at the upper 



part. 

 Philippi, Pro. Zool. Soc. 1845, p. Ul. 

 Hab. Sitka, 



A duU-white shell, sometimes speckled with red, chiefly 

 distinguished by the regularity with which it is spirally 

 grooved. 



