malacology(n = noun.cognition) - the branch of zoology that studies the structure and behavior of mollusks;
is a kind of zoological science, zoology
has particulars: conchology, shell collecting

   The science which relates to the structure and habits of mollusks. [1913 Webster]

malacology, n. the study of molluscs.

N  zoology, zoonomy, zoography, zootomy, anatomy, comparative anatomy, animal physiology, comparative physiology, morphology, mammalogy, anthropology, ornithology, ichthyology, herpetology, ophiology, malacology, helminthology, entomology, oryctology, paleontology, mastology, vermeology, ornithotomy, ichthyotomy, taxidermy, zoologist, zoological.