mollusca

The mollusca are animals with soft bodies, enveloped in a muscular skin, and usually protected by a univalve or bivalve shell. […] The univalve mollusca are encephalous, or furnished with a distinct head; they have eyes and tentacula, and the mouth is armed with jaws.

1851, S[amuel] P[ickworth] Woodward, “Classes of the Mollusca”, in A Manual of the Mollusca; or, A Rudimentary Treatise of Recent and Fossil Shells, London: John Weale, […], page 6

Turning for a very brief space to animals: on the land there are some hermaphrodites, as land-mollusca and earth-worms; but these all pair.

1859 November 24, Charles Darwin, “Natural Selection”, in On the Origin of Species by Means of Natural Selection, […], London: John Murray, […], →OCLC, page 100

The amphibious animals are provided with special organs for the sense of smell, although a very delicate sense of smell is likewise met with among the crustacea, such as crabs, mollusca and insects.

1862, Arthur Lutze, translated by Charles J[ulius] Hempel, “[Appendix.] The Human Body”, in Manual of Homœopathic Theory and Practice. Designed for the Use of Physicians and Families., New York, N.Y.; Philadelphia, Pa.: […] William Radde, […], page 532

Probably frogs, crabs, mollusca, and insects form their chief diet; […]

1886 July, Keswal [pseudonym; W. F. Sinclair], “Notes on the Waters of Western India. Part I.—‘British Deccan and Khandesh.’”, in R[obert] A[rmitage] Sterndale, E[dward] H[amilton] Aitken, editors, The Journal of the Bombay Natural History Society, volume I, number 3, Bombay: […] [T]he Education Society’s Press […], page 114

The gentle slopes are favorable to the growth of various mollusca whose hard parts contribute additional material to the growing limestones.

1940, Frank F[itch] Grout, “[The Sedimentary Rocks] Limestones”, in A Handbook of Rocks for Use Without the Petrographic Microscope, 6th edition, New York, N.Y.: D. Van Nostrand Company, Inc., […], page 169