(old source from 1892 was used, some of these names may be synonyms): Tryon (1884)[1] wrote about the genus Hyalimax (while mentioning Hyalimax pellucidus as an example) like this: "Animal limaciform, swollen at centre, blunt before, and tapering behind; tentacles simple; mantle large, central, concealing all but a small opening; an internal shell-plate; no longitudinal furrows above the margin of the foot, and no caudal mucous pit; no distinct locomotive disk; external respiratory and anal orifices on the central right margin of the mantle; orifice of combined genital system on right side of head, halfway between eye-peduncle and mantle."

"Shell large, rudimentary, thin, oval, unguiform, non-spiral.

Jaw smooth with blunt median projection and accessory quadrate plate.

Lingual membrane with tricuspid central teeth, multifid laterals, and quadrate marginals."

This article incorporates public domain text from the reference[2] (distribution localities were cited) and from.