Abstract
Kaasichiton n. gen. from the northwestern part of the Pacific Ocean is described here. The genus includes four species, all of them are brooding. Two of them, K. lukini and K. incubatus, are transferred from the genus Leptochiton to the new genus, two more, K. ionensis n. sp. and K. kamchatkensis n. sp., are described as new. The new species increase the number of brooding chiton species to 44. Species of the new genus display a considerable variability regarding radular features. This has implications for the significance of these features within other genera, for which a similar variability has been observed.
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