SYSTEMATIC DESCRIPTION. 
Group BRTOZOA, Ehrenberg, 1831. 
Class ECTOPROCTA, Nitsche. 
Subclass GYMNOL^MATA, Allman. 
Order CTCLOSTOMATA, Busk. 
Bryozoa in wRich the zooecia are simple, elongated, and cylindrical, 
and typically grow in tufts or sheets formed of radiating zooecia. 
Mesopores are rarely, if ever, present. Mouths circular, and 
generally raised above the surface of the zoarium. Ooecia of 
enlarged zooecia. Appendages generally absent. 
Suborder TIJBULATA, Gregory. 
Zoarium formed of monomorphic zooecia, not divided into inter- 
nodes ; zooecia of elongated tubes grouped into bundles or sheets, 
or linear series. 
Family DIASTOPORID^. 
Diagnosis. 
Cyclostomata Tubulata in which the zooecia are simple, open 
tubes, which either grow as linear series or as encrusting or 
erect sheets. The sheets may he coiled into hollow tubes. 
The zoarium is exceptionally massive. The zooecia may be 
wholly immersed or partly free. Appendages absent. 
B 
