The Collaborative International Dictionary of English v.0.48:

Halichondriae \Hal`i*chon"dri*[ae]\
   (h[a^]l`[i^]*k[o^]n"dr[i^]*[=e]), prop. n. pl. [NL., fr. Gr.
   "a`ls, "alo`s, sea + cho`ndros cartilage.] (Zool.)
   An order of sponges, having simple siliceous spicules and
   keratose fibers; -- called also Keratosilicoidea.
   [1913 Webster]