The Periwinkles and Chink Shells 



L. littorea. We look for both species on rocks between tide marks, 

 and in stagnant pools and marshes. They seem to avoid the dash 

 of the surf, though they are built to resist harm from wave action. 

 Length, i inch. 



Hahitai.—¥\ond2i to New York. 



The Rough Winkle (L. rudis, Don) is at best scarcely half 

 an inch in length, with rounded whorls separated by deep sutures. 

 The female carries her eggs until they hatch, hence the last whorl 

 isfully two-thirds of the whole shell and the round mouth is much 

 larger than that of a male shell of equal size. This species is 

 banded in neutral colours, from yellow to black. It can live out 

 of water for a week. Marked specimens on the rocks were found 

 not to have moved for over a month. The shells of the young 

 brood render these periwinkles inedible. Their size, also, makes 

 them hardly worth while. Length, ^ to ^ inch. 



Habitat. — Atlantic and Pacific coasts. 



The Gray Littorina (L. planaxis, Nutt.) is known by the 

 broad, flat excavation of the columella. The shells are smooth 

 rather thick, dirty white, flamed in irregular, often handsome 

 patterns. The young shells lose their brightness with age. The 

 average diameter is h inch. 



Habitat. — California. 



The Checkered Littorina (L. scutellata, Gld.) is brown or 

 olive, checkered with white. The average shells are ^ inch or 

 less in length. It is a very variable species. 



Habitat. — West coast of United States. 



The Zigzag Periwinkle (L. {iciac, Dillw.), has a tall spire, 

 angled at its periphery, and decorated with fine, zigzag stripes 

 of brownish yellow from apex to base. The body whorl shows 

 a median clouding of blue that is faintly seen on the upper whorls. 

 The species is variable. Length, h to i inch. 



Habitat. — Texas, Florida Keys, West Indies. 



L. angulifera, Lam., is distributed on the Florida and Gulf 

 coasts and in the West Indies. 



Genus TECTARIUS, Val. 



The Pagoda Littorina {T. Pagod, Linn.) is very much like 

 a Chinese pagoda, with a row of upturned, triangular tubercles 

 finishing the keeled margins of its whorls. Secondary tubercles 



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