HELIOZOA 21 



P. mutabilis Bailey. Body compressed and ovate or pear-shaped; 

 protoplasm yellowish in color ; length 1 mm. : in swamps. 



P. hyalinus Leidy. Body almost spherical with short neck; often 

 colonial; length .04 mm. 



3. DIPLOPHRYS Barker. Shell spherical and membranous and with 

 two openings opposite each other, from which protrude the pseudopodia : 

 2 species; in fresh water. 



D. archeri Barker. Pseudopodia not always anastomosing; length 

 .02 mm. 



DIVISION 3. PERFORINA. (FORAMINIFERA.) 



Calcareous shell, either one or many chambered, and with numerous 

 minute pores, as well in some cases as large openings, through which 

 stream reticulate pseudopodia: 9 families with numerous genera and 

 over 1,200 species, most of which live in the mud of the sea bottom, about 

 20 species being pelagic. 



FAMILY GLOBIGEBINIDAE. 



Shell calcareous and one or many chambered with one or more large 

 openings: about 7 genera. 



GLOBIGERINA D'Orbigny. Shell with many chambers which are 

 more or less ovoid and spirally arranged; large openings crescentic; 

 usually with spines: about 13 species; marine. 



G. bulloides D'Orb. Animals pelagic and also in the bottom mud 

 at all depths down to 3,000 fathoms: cosmopolitan. 



ORDER 2. HELIOZOA.* 



Sarcodina with little power of amoeboid movement, with a silicious 

 skeleton and fine ray-like pseudopodia which are often supported by 

 silicious axial filaments; ectosarc and entosarc usually sharply marked; 

 contractile vacuole present in the fresh-water forms, but absent in the 

 marine ones; either one or several nuclei present; reproduction either 

 by equal division or by spore formation, the spores being flagellate 

 and after an active life losing their flagella and assuming the form of 

 the adult; conjugation and encystment also occur: about 50 species, 

 grouped in 4 suborders; mostly in fresh water, but also in the sea and 

 in moist earth. 



Key to the suborders of Heliozoa: 

 a t Heliozoa without skeleton. 



&! Body naked 1. APHROTHOBACIDA 



6 2 Body with a soft gelatinous or felted fibrous covering. .2. CHLAMYDOPHORIDA 

 2 Heliozoa with skeleton. 



&i Skeleton consists of spicules 3. CHALARATHOBACIDA 



Z> 2 Skeleton consists of a single piece perforated by numerous openings. 



4. DESMOTHOP.ACIDA 

 * See "Heliozoa," by F. Schaudinn, Das Tierreich, 1896. 



