periwinkle

…A general term for a group of snail shells in the family Littorina. The Littorina brevicula (periwinkle) (illustration) has a shell that is 1.4 cm high and 1.7 cm in diameter. The shell is thick and solid, the spiral spire is conical, and the body layers are large. There are usually two strong spiral ribs on each layer and three strong spiral ribs on the body layer, with some thin spiral ribs between them.

*Some of the terminology that mentions "periwinkle" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…タマキビガイ科の巻貝の総称，またはそのうちの1種を指す。タマキビガイLittorina brevicula(英名periwinkle)（イラスト）は殻の高さ1.4cm，径1.7cmに達する。殻は厚く堅固で螺塔（らとう）は円錐形，体層は大きく，通常各層に2本，体層に3本の強い螺肋があり，その間に細い螺肋もある。…

※「periwinkle」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報