XX KEY TO THE FAMILIES. 



Class Polyzoa. 



Aggregated together in shelly or horny cases. 



(a.) Cells more or less ovoid ; mouth less than the diameter of the cell. 

 (Figs. 2 and 6.) 



1. Polyzoarium of distinct pieces connected by flexible joints. 



CATENICELMD^:. Cells in a single series ... ... ... 88 



CELLTTLABIID^:. Cells in a double series ... ... ... 89 



SALICOBNABIID^:. Cells disposed round an imaginary axis ... 90 



2. Polyzoarium continuous throughout. 



* Flexible, never adnate. 



ScEUPAEiAD.ffi. Cells in a single series ... 91 



CABEEEID.E. Branched ; cells in the same plane ; furnished with 



bristles 



BICELLAEIID^;. Branched ; cells in the same plane ; no bristles 92 

 FARCIMINABIID.E. Branched ; cells disposed round an imaginary 



axis ... ... ... ... 94 



G-EMELLABIIM:. Branched; cells in pairs ... ... ... 95 



FLUSTEnxffi. Foliaceous, entire or lobed ... ... 93 



* * Rigid, adnate or erect. 



MEMBBANIPOBIDJE. Crustaceous, spreading ... ... ... 95 



CELLEPOBID.E. -Massive ; cells sub-ei-ect and confusedly heaped 98 



ESCHAEHXE. Erect; fixed ... ... ... 99 



(&.) Cells tubular; mouth of the same diameter as the cell. (Fig. 1.) 



1. Marine. 



CEISIID^;. Branched, more or less flexible ... ... ... 100 



IDMONEIM:. Erect, branched ... ... ... ... 101 



TTJBTILIPOEID^;. Adnate, divided into lobes ... ... ... 103 



DIASTOPOBID^;. Discoid, sessile or pedunculate ... ... 103 



2. Freshwater. 



PLTJMATELLIM:. Adnate, branched ... ... ... ... 104 



Class Tunicata. 



Enclosed in a leathery skin. 



(a.) Animal fixed. 



ASCIDIAD^E. Animal simple ... ... ... .. ... 104 



BOTEYLLID.S:. Animal compound ... ... ... ... 105 



(6.) Animal free, floating. 



PTEOSOMiD.ffi. Animal compound ... ... ... ... 105 



. Animal simple, sometimes aggregated ... ... 106 



