112 



THE AMERICAN MONTHLY 



[April 



as long as wide : plastic and changeable in shape ; ven- 

 trum slightly r(Micave ;iiiteriorly ; flagella originating 

 together at the anterior extremity, the anterior vibratile 

 Hagellum nearly one half the body length ; this tlagelluni 

 is heavy strap-like and of uniform thickness from its ori- 

 gin to its distal end; the trailing fla^ellum from tAvo to 

 two and a half times the body length ; contractile vesicle 



1. — ActiuomoDuij primus, x 'JlKJ. 



i. — Aifiiimnnirris ii;teitnediatest ' . 



•^. — Artiiionioiia.i. Hi-lio/.naii I'li i 



4. — Heteromila lif;iilrtta. x llOn. 



5. — PetaliiiiKiuiis |>ii»illa. x 'i'iSO. 



fi. — Atractunema fugifuiniis, x 17o(i. 



7. — Diiildiiiaslix roatriiin. x H(l(). 



S. — Dipliiiuastix aKiliH. x 12(Hi. 



I'. — Diploniastix lalero-vnitral view. 

 10. — Aiiigonema disoniato. x 1250. 

 11. — Anisunenia. Transverse section. 



conspicuous and situated close to the anterior extremity; 

 nucleus round and located in the posterior body half; 

 endoplasm, hyaline and slightly grauuhir; locomotion 

 sb)\v and equable while the anterior strap-like tlagellum 

 is constantly and rapidly wagged. Size from 1-5000 to 

 1-3000 inch. 



Habitat — Ubiquitous. Transverse fission. 



