• (n.) The science which treats of testaceans, or shellfish; the description of shellfish.
Tes·ta`ce·og'ra·phy noun [ Testacea + -graphy : confer French testacéographie .] The science which treats of testaceans, or shellfish; the description of shellfish. [ R.] 
testaceography The science concerned with testaceans, or shellfish; the description of shellfish.