Bank reviewed the nomenclature of the species and established bulverii as the original spelling of the species name although most authors in the last 80 years have used the bulweri spelling. 

Seddon (2008) noted that 'there has been debate since the 1860s as to whether D. bulweri and D. albersi are one or two species. Wollaston (1878) maintained two species based on Lowe's descriptions commenting that both were found together. D. albersi was treated as subspecies of D. bulweri by Mandahl-Barth (1950), but as separate species by Walden (1983).  Nobre (1931) and Bank et al. (2002) view albersi as a synonym of bulweri.  Seddon (2008) reviewed  extensive material in Museum collections and suggests that the two forms are not separable on a consistent basis, therefore albersi is placed as a synonym of bulweri.  Wollaston (1878) noted the similarity to D. lyelliana from Deserta Grande.

This species has a restricted area of occupancy of 8 km². There is concern for the survival of this species, as this large helicid has multiple threats: there are problems of competition with other introduced helicids such as Theba pisana, impact of over-grazing within the habitat on the lower slopes of the hills and evidence that a rodent is predating on this species as well as others with similar shell size and form (Seddon 2008). Although the species is found around the base of two hills, it is considered as single location, as rodents are predating on the species across the range. On a precautionary approach, the species is considered to be Critically Endangered (CR) B2ab(iii). Conservation actions needed include removal of the rodent predation as well as protection of the habitat.

The previous assessment for this species was based on the A criteria, however there is insufficient data on population trends to establish whether the loss of the mature adults continues to meet the decline rates for Critically Endangered, hence more data is required on this species.

This species is endemic to the Madeiran islands, where it is restricted to eastern end of Porto Santo where it is mainly found on the lower slopes around two hills, both in close proximity (Seddon 2008).

The species suffers from predation by introduced rodents and adults are impacted. The species is not abundant and it is thought to be a slow-maturing species which is more vulnerable than the smaller-bodied gastropods, as their reproductive success is impacted by loss of adults. Many shells can be found in small clusters with their apices eaten out, and this species has a less robust shell than the other taxa, so is easier to break into.

This species is found on the ground, on rocks and amongst low growing grasses and herbs in Porto Santo.

This large-shelled gastropod has multiple threats: there are problems of competition with other introduced helicids such as Theba pisana, impact of over-grazing within the habitat on the lower slopes of the hills (R. Cameron pers. comm. 2010) and evidence that a rodent is predating on this species as well as on others with similar shell size and form (Seddon 2008). The rodents predate on adults; these slow-maturing species are more vulnerable than the smaller-bodied gastropods, as their reproductive success is impacted by loss of adults.

The species is not known to be utilised, although occasionally sold by shell collectors.

Further monitoring on population status and impact of rodents is required to establish future trends in decline.