The Mt. Kahuzi Climbing Mouse was described in 1969; the species is known only from two specimens, a male and a female that were collected in 1967 and 1972 respectively.
The species is (or was) known only from the forests at Mount Kahuzi in the Democratic Republic of the Congo; it is highly threatened by illegal logging and habitat destruction and, having never been found since 1972, might actually already be extinct.
This species was described in 1942, it apparently was restricted to the Congo River, where it inhabited crevices among rocks in swiftly flowing water near the town of Matadi in the Democratic Republic of the Congo.
The shells reach sizes of about 1,2 cm in height.
The species is considered extinct, however, I didn’t find any additional information about thus assumption.
This remarkable highly specialized plant species was endemic to the Democratic Republic of the Congo, where it was restricted to copper-rich soil.
The species disappeared, together with several other highly specialized species, due to habitat loss by copper mining. 
 Michel-Pierre Faucon; Arthur Meersseman; Mylor Ngoy Shutcha; Grégory Mahy; Michel Ngongo Luhembwe; François Malaisse; Pierre Meerts: Copper endemism in the Congolese ﬂora: a database of copper afﬁnity and conservational value of cuprophytes. Plant Ecology and Evolution 143(1): 5-18. 2010