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Crass I.—Hyprozoa. 
Ccelenterate animals, in which the wall of the digestive sac is iden- 
tical with that of the general cavity of the body, and the reproductive 
organs are external. 
Order 1.—Hydride. 
Animal consisting of a single naked polype. Locomotive. 
Order 2.—Tubularide. 
Animal consisting of one polype, or of several connected by a 
“‘cenosare.”’ Fixed. Polypes naked. 
Order 3.—Sertularide. 
Animal consisting of several polypes, connected by a ceenosarc. 
Fixed. Polypes protected by cells. 
Order 4.— Calycophoride. 
Animal consisting of several polypes, connected by a cenosarc, 
furnished with natatorial organs. Oceanic. 
Order 5.—Physophoride. 
Animal consisting of several polypes, connected by a cenosare, with 
or without natatorial organs. Upper extremity of cenosare dilated 
into a ‘‘ float.” Oceanic. 
Order 6.—Meduside. 
Animal consisting of a polype suspended from the under surface of 
a natatorial organ. Oceanic. 
Order 7.—Lucernaride. 
Animal consisting of a polype situated in the centre of a natatorial 
organ furnished with adherent base. Fixed or locomotive. 
Crass I].—Actrnozoa. : 
Ccelenterate animals, in which the wall of the digestive sac is sepa- 
rated from that of the general cavity of the body by an intervening space, 
subdivided into chambers by a series of vertical perigastric partitions, 
on the sides of which the reproductive bodies are situated. 
a. Parts of the body in number some multiple of five or six. 
Order 1.—Zoantharia. 
Polypes with simple (rarely branched) tentacula, usually numerous. 
Solitary or aggregated. Sedentary or locomotive, seldom oceanic. 
b. Parts of the body in number some multiple of four. 
Order 2.—Rugosa. 
Animal unknown. Corallum thecal, with septa and tabula. 
