(Latin plural genera), 1550s as a term of logic, "kind or class of things" (biological sense dates from c. 1600), from Latin genus (genitive generis) "race, stock, kind; family, birth, descent, origin" (from suffixed form of PIE root *gene- "give birth, beget," with derivatives referring to procreation and familial and tribal groups).

"cartilaginous fish resembling or related to a shark of the genus selachii," 1835; the genus name from Latinized form of Greek selakhos (plural selakhē) "cartilaginous fish," which is of uncertain origin.

plural of genus.

horseshoe crab, king crab, representative genus of the biological family Limulidae, 1837, Modern Latin, from Latin limulus "somewhat askance," diminutive of limus "askance." The genus classification involved the number and position of the eyes.

"genetic constitution of an individual," 1910, from German Genotypus (Wilhelm Johannsen, 1909); see gene + type (n.). Earlier the same word was used with a sense of "type-species of a genus" (1897); in this case, the first element is from genus.

genus of mulberry trees, from Latin morus "mulberry tree."

"parasite of the genus Schistosoma" (1905); the genus name (1858) is a Modern Latin formation from Greek skhistos "divided, cloven" (from skhizein "to split;" see schizo-) + sōma "body" (see somato-). Related: Schistosomatosis "disease caused by schistosomes" (1906).

genus of fungi, Modern Latin, from Greek pilos "felt" (see pileated) + bōlos "a clod, clump."

"Australian duck-mole," 1799, from Modern Latin, from Greek platypous, literally "flat-footed," from platys "broad, flat" (from PIE root *plat- "to spread") + pous "foot," from PIE root *ped- "foot." Originally the genus name, but entomologists had given it earlier to a genus of beetles; it was retained for the species after the genus name was changed in 1800 to Ornithorhyncus. OED has Australian platypussary (1945) "enclosure in which platypuses are kept."

shrub genus, 1846, from the name of German physician and botanist C.E. Weigel (1748-1831).