Shell from 20 to 50 mm in height, ovate to elongate-ovate, with a gradate, subcorneal or turbinate spire of four to six weakly to prominently shouldered or convex whorls. Protoconch of one to 1,5 whorls, planorbid or somewhat irregular in shape, in some species sunken below first teleoconch whorl, in most coiled with axis of shell. Sutures impressed in most species, channelled in a few.
Spiral sculpture of close-set, fine lirae appearing on first teleoconch whorl and present over whole whorl of most species. Axial sculpture of strong to weak tubercles or plicae appearing on third or later whorls of most species; absent in very few.
All last whorl of most species and up to all of penultimate whorl of some species covered in thick callus, obscuring all underlying sculpture, with narrow posterior sutural channel in many species. Callus sculptured with weak to coarse, bisinuous growth striae and with obscure spiral cords in some species. Aperture lenticular, weakly notched posteriorly in many species, notched anteriorly in all species; columella arched, covered by thin glaze, glaze develops into thick callus pad in some species; outer lip bisinuous and produced adaperturally at the anterior third. Siphonal fasciole present, but weak in most species.

Stratigraphic range. Early Miocene-Recent.
Distribution. Southern and eastern Australia. New South Wales (Recent); Victoria (Late Miocene-Early Pliocene); Tasmania (Early Miocene, Late Pliocene); South Australia (Late Miocene-Late Pliocene); Western Australia (Late Pliocene-Early Pleistocene).

Tylospira is distinguished from most other struthiolariids by the tylospirid growth habit (Marwick, I960). This involves a change in style of growth in mature specimens, whereby a thick layer of callus is deposited around the aperture from a certain point in the development of the shell. This deposition continues in some specimens for another half to two whorls. The callus frequently overlaps the suture onto the preceding whorl and all underlying sculpture is covered. The only other struthiolariids that have a similar style of growth arce Conchothyra Hutton from the Late Cretaceous to Early Tertiary of New Zealand and Antarctodarwinella Zinsmeister from the Late Eocene of the Antarctic Peninsula. In the former the callus is much thicker, not glazed and covers the entire shell surface, burying the spire. In the latter there is a prominent posterior sinus in the outer lip, the siphonal fasciole is much stronger, the callus is heavier and prominently laminated and the outer lip extends much further beyond the plane of the aperture. The morphological similarities between these three genera are therefore thought to be due to convergence.