CHROMOSOME NUMBER IN TWO PHENOTYPICALLY DISTINCT POPULATIONS OF LITTORINA SAXATILIS OLIVI, AND IN SPECIMENS OF THE LITTORINA OBTUSATA (L.) SPECIES-COMPLEX

Chromosome numbers counted from embryo cells of the marine gastropodLittorina saxatilis (=L. rudis), were the same, 2n = 34, inpopulations of two different phenotypes from a small area inSweden. Chromosome number in the related species-complex, Littorinaobtusata, could not be determined definitely, but the most adequatefigure seemed to be 2n = 34. (Received 9 September 1982;