Protozoa and Rotifer a at Havana, III. 315 



2. Suborder Testacea. Shelled forms; pseudopodia 

 lobose or filiform. Four fresh-water families. 

 Arcellidce. Shell homogeneous or incrusted with 

 sand grains or other foreign material ; pseudo- 

 podia lobose. 

 Euglyphidce. Shell built of round or hexagonal 

 plates ; pseudopodia filiform at tip. 



2. Subclass Heliozoa. Body usually globose; pseudo- 

 podia thread-like, constant, radiating in all directions. 



1. Order Aphrothoraca. Naked, or with gelatinous 

 envelope. 



2. Order Chalarathoraca. Coated with silicious bodies 

 of a definite form, spicular, discoid, etc. 



3. Order Desmothoraca. Skeleton shell nearly or quite 

 spherical, latticed, with numerous openings. 



3. Subclass RadAolaria. Body globose, with a silicious 

 shell; pseudopodia filiform, radiating in all directions. 

 Marine. 



II. Class Sporozoa. Parasitic forms, multiplying exclusively 



by spore formation. 



III. Class Mastigophora. Provided with one or more vibra- 



tile anterior or lateral flagella ; body not ciliated. 



1. Order Flagellata. One or more anterior, rarely 

 lateral, flagella, not encircled by a membranous 

 collar; body naked or loricated. 



2. Order Choanoflagellata. One anterior flagellum, 

 encircledby one or two thin membranous raised col- 

 lars. 



3. Order Dinoflagellata. Two flagella, anterior or 

 lateral (if we consider the advancing pole in loco- 

 motion as the anterior end), one directed longitudi- 

 nally, the other transversely, and usually encircling 

 the body more or less ; body with a shell or armor ; 

 no definite mouth. 



4. Order Cystqflagellata. Large, phosphorescent ma- 

 rine forms. 



IV. Class Infusoria. Clothed with cilia, entirely or in part ; 

 cilia variously differentiated and modified. 



