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26 a. Lorica present, i.e. cuticle thickened to form a stiff shell

     (lorica), which retain its shape well after preservation.

      Lorica strongly flattened, circular in outline, foot opening

      ventral, and foot ends in circle of cilia (se 16b)

          Testudinella.................................................68

26 b. Lorica absent, i.e. cuticle thin and flexible, not usually

retaining its shape well after preservation. A gelatinous,

transparent case around foot and part of the

body............................................................27

 

27 a. Head more or less funnel-like. Foot long and slender, stalk-like.

Single animal in very transparent gelatinous case, usually

contracted. Most species littoral, few planktonic species.

          Collotheca...................................................77

27 b. Head not funnel-like. Foot fairly stout. Solitary (Conochiloides) 

or in colonies (Conochilus). Formalin-preserved specimens 

separated from gelatinous case. Formalin-sugar-preserved specimens 

still in gelatinous case, usually strongly contracted. Antenna 

present, planktonic.

          Conochilus (incl. Conochiloides).............................74

 

28 a. Body with spines or with blade-like or arm-like processes........29

28 b. Body without this................................................32

 

29 a. Cuticle thickened to form a stiff shell (lorica) retaining its 

shape well after preservation. Often ornamented with ridges or 

striations. Body with anterior and usually 1 or 2 posterior 

spines. Planktonic.

          Keratella....................................................49

29 b. Cuticle thin, transparent, not usually retaining its shape well

        after preservation...............................................30

  

30 a. Body with 6 arms with setae. Nauplius-like. Planktonic.

          Hexarthra....................................................73

30 b. Body with spines or feathers.....................................31  

 

31 a. Body with long spines, 2 anterior and 1 (Filinia) or 2 

(Tetramastix) posterior spines. Planktonic.

          Filinia (incl. Tetramastix)..................................71

31 b. Body with 12 blades or feathers in 4 groups of 3 blades, 2 groups

dorsoventrally and 2 groups ventrolatterally. Planktonic.

          Polyarthra...................................................66

to 32 a.