Three new species from the Aleutian Islands are described. Echinoclathria seguama n. sp. has only four congeners in the region, it is closest to E. vasa and differs from it in the dimensions of all spicule categories. Stelodoryx jamesorri n. sp. is unusual as it has a plumoreticulate choanosomal skeleton instead of the usual reticulate arrangement in other Stelodoryx. To accommodate the species in Stelodoryx we amend the genus definition accordingly. Choanosomal styles, common in Stelodoryx, tend to merge into strongyloxeas in S. jamesorri. Additionally, spicule dimensions deviate from other congeners of the region. The tendency of replacing choanosomal styles by strongyloxeas goes even further in Stelodoryx strongyloxeata n. sp. which has very conspicuous, thick, fusiform strongyloxeas, that differ, apart from being strongyloxeas, also considerably in size from the styles of other species. S. strongyloxeata n. sp. also has style-like tornotes, a characteristic that it shares with S. siphofuscus, but dimensions of style-shaped tornotes are different.