"bearing a cross," 1650s, from Late Latin crucifer "cross-bearing," from Latin crux (genitive crucis) "stake, cross" (see crux). Originally in literal senses; botanical use (in reference to a symmetrical arrangement of four petals) is from 1851.
"the sponges," as an animal division or class, 1843, Modern Latin, literally "bearing pores," neuter plural of porifer, from Latin porus "pore, opening" (see pore (n.)) + -fer "bearing" (from PIE root *bher- (1) "to carry"). So called for the numerous pores which perforate the body-wall. Related: Poriferal; poriferous.