LISTS OP FRESH- WATEE EHIZOPODS. 293 



III. EHIZOPODS OBSEEVED IN SLIME WITH MOSS AND ALG.E SCRAPED 

 FROM THE VERTICAL FACE OF DRIPPING GNEISS ROCKS OF 

 FAIRMOUNT RESERVOIR, PHILADELPHIA, JULY 6, 1879. 



1. Dtpflugia constricta. Occasional, and merging into forms which might be 



equally well viewed as the variety Centropyxis ecomis; 0.09 mm. long, 0.078 mm. 

 broad, and with mouth 0.030 mm. wide. An unusually long specimen was 0.12 

 mm. long, 0.072 mm. in the greater and 0.054 mm. in the less breadth. When 

 the mouth was on a level it stood 0.06 mm. high. All specimens of a yellowish 

 hue. 



2. Centropyxis aculeata. Small, of yellowish chitinoid membrane incorporated 



with sand, and usually with two or three spines. Length 0.072 mm. ; breadth 

 0.06 mm. ; width of mouth 0.03 mm. 



3. Eugltpha alveolata. Small, spineless form ; abundant. Shell ovoid; trans- 



verse diameters uniform, rarely slightly compressed ; fundus obtuse, rarely in 

 the smallest acute; mouth with 4, 6, or 8 teeth, the number not in accordance 

 with size. More dead shells than living specimens ; many with the sarcode 

 apparently resolved into spores, which were shining, oil-like globules, from one 

 or two to half a dozen or more in number, and of pretty uniform size, being 

 about 0.012 mm. Specimens mostly 0.066 mm. to 0.072 mm. long, 0.036 mm. to 

 0.042 mm. broad, and 0.018 mm. wide at the mouth. Ranging from 0.033 mm. 

 to 0.09 mm. in length, by 0.012 mm. to 0.042 mm. in breadth. Nucleus of the 

 sarcode about 0.018 mm. Variety : several dead shells with the mouth obUque 

 or subterminal ; 0.06 mm. in length, 0.036 mm. in breadth, and 0.0135 mm. wide 

 at the mouth. Variety: with a slight curvature approaching the mouth. A 

 living specimen 0.06 mm. in length, 0.036 mm. in breadth, and 0.012 mm. wide 

 at the mouth. 



4. Euglypha ciliata. One living specimen observed. Shell ovoid, compressed, 



with three spines to one side, two to the other, and one to the fundus ; mouth 

 with four thickened teeth. Length 0.06 mm. ; greater breadth 0.024 mm. ; at 

 mouth 0.009 mm. Resembled fig. 14, pi. xxxvi. 



5. Trinema enchelys. Mostly dead shells, small, and frequent. The cancellated 



structure not visible in the smaller but distinct in the larger ones. From 0.03 

 mm. to 0.078 mm. in length, 0.012 mm. to 0.042 mm. in breadth. Several with 

 the sarcode encysted, and several with the latter resolved into spores. A pair 

 of empty shells, observed adhering mouth to mouth, as in conjugation, and dis- 

 posed in the same direction, and not in opposite directions as previously noticed. 

 One of the shells 0.042 mm. long, the other 0.03 mm. long. 



6. Actemophrys SOL. Occasional ; in active condition. A pair observed either in 



conjugation or act of division. 



7. Amceba radiosa. Few. 



8. A. verrucosa. Young condition as A. quadrilineata. 



9. A. proteus? Young. Occasional. 



