SPECIAL MORPHOLOGY AND TAXONOMY OF INFUSORIA 409 



Family 1. Halteriidse, Clap, and Lach. 



1. Spheroidal; central girdle of bristle-like 



cilia Genus Halteria 



Spheroidal or urn-shape; no girdle of cilia 2 



2. Periplast delicate 3 



Posterior periplast hardened and test-like 



Genus Laboea 



3. With distinct tail-like appendage. . .Genus Tontonia 

 Without caudal appendage Genus Strombidhmi 



Family 2. Tintinnidae, Clap, and Lach. (Mainly after Jorgensen, 1899). 



1. Test soft and gelatinous Genus Tintinnidium 



Test rigid, chitinous 2 



2. Test open at both ends Genus Ttntinnus 



Test open at anterior end only 3 



3. Test with anterior decorations 4 



Test plain without anterior trimmings .... 5 



4. Anterior perforated by large openings 



Genus Dictyocysta 

 Anterior openings absent or feeble . . Genus Codonella 



5. Test wall double with alveoli Genus CyttarocycUs 



Test wall double without alveoli .... Genus Undella 

 Test wall single, simple 6 



6. Test ornamented Ijy pleats or sculpturing 



Genus Ptychocydis 

 Test with adherent foreign particles (Fig. 



174, p. 391) Genus Tintinnopsis 



Test without foreign bodies or ornaments 



Genus Amphorella 

 Family 3. Ophryoscolecidae, Stein. 



1. With one circle of membranelles 2 



With two circles of membranelles 3 



2. Two posterior bundles of cilia (Caudalia) 



Genus Cycloposthvmn 

 No caudal cilia, long caudal spine. .Genus Entodinium 

 Four incomplete girdles of long cilia Genus Troglodytella 



3. Dorsal circlet includes more than half the 



body Genus Ophryoscolex 



Dorsal circlet includes less than half the 

 body (Fig. 2, p. 20) Genus Diplodinium 



Order IV. HYPOTRICHmA, Stein. 



1. Ventral surface with uniform cilia; no cirri 



Famih' 1. Peritrojiid.e 

 At least anal cirri on ventral surface 2 



2. Except anals, no ventral cirri posterior to 



mouth Family 2. Urostylid.e 



With posterior ventral cirri 3 



3. With cilia in addition to cirri 4 



Cilia entirely replaced by cirri 5 



4. Five to eight frontal cirri; cilia in one or 



more rows Family 3. Pleurotrichid.e 



Frontal and ventral cirri reduced; no cilia 



Family 4. Psilotrichid.^ 



5. With lateral, ventral, frontal and anal cirri 



Family 5. Euplotid.e 

 No lateral; variable frontals, ventrals, and 



anals Family 6. Aspidiscid.e 



