The Ancylus age is followed by formation of the Littorina Sea and the Litorina Stage ( named after the " Littorina littorea " mollusc ) at around 6200 BC.
22.
Others prefer to include it in the Littorina Sea stage as a transitional phase after the establishment of the marine connection ( Hyv�rinen " et al . " 1988 ).
23.
There are more than fifty species in this genus of which more than 20 species are believed to be synonyms of " Littorina scabra ", a very variable species.
24.
""'Littorina aleutica " "'is a species of sea snail, a marine gastropod mollusk in the family Littorinidae, the winkles or periwinkles.
25.
""'Littorina arcana " "'is a species of sea snail, a marine gastropod mollusk in the family Littorinidae, the winkles or periwinkles.
26.
""'Littorina brevicula " "'is a species of sea snail, a marine gastropod mollusk in the family Littorinidae, the winkles or periwinkles.
27.
""'Littorina compressa " "'is a species of sea snail, a marine gastropod mollusk in the family Littorinidae, the winkles or periwinkles.
28.
""'Littorina fabalis " "'is a species of sea snail, a marine gastropod mollusk in the family Littorinidae, the winkles or periwinkles.
29.
""'Littorina horikawai " "'is a species of sea snail, a marine gastropod mollusk in the family Littorinidae, the winkles or periwinkles.
30.
""'Littorina kasatka " "'is a species of sea snail, a marine gastropod mollusk in the family Littorinidae, the winkles or periwinkles.
