Page:Scientific results HMS Challenger vol 18 part 2.djvu/19

Rh We divide the immense legion of into two large orders, the  without complete lattice-shell, and the  with a complete lattice-shell or a "cephalis," including the central capsule; the latter, of course, have arisen from the former. The comprise three different suborders, the  (without skeleton), the  (with a tripodal skeleton, without ring), and the  (with a primary sagittal ring, with or without tripod). The again also comprise three different suborders, the  (with bilocular cephalis and a sagittal constriction), the  (with multilocular and lobate cephalis, exhibiting two or more constrictions and three or more lobes), and the  (with simple, unilocular cephalis, without constriction).

Definition.— without complete lattice-shell, usually with an incomplete skeleton, formed of a ring, a tripod, or an irregular framework.

Definition.— without skeleton. Single family Nassellida.