GENUS OUEAMGEBA— OUEAMCEBA BOTULICAUDA. 71 



'Navicula major at times extended across the back part of the body, and 

 then again was dragged along behind in a pouch-like extension of the same. 



Another fine active specimen, observed on the same occasion, is repre- 

 sented in fig. 6. It was much branched, and was 0.2 mm. long. The 

 caudal filaments formed three tufts and ranged from 0.05 to 0.16 mm. in 

 length. The animal dragged after it a considerable amount of dirt, which 

 adhered at the point of origin of the caudal filaments. 



Another specimen, with the body ramose, and 0.22 mm. long by 

 0.2 mm. in expanse, had but a single pair of caudal filaments. It con- 

 tained two large specimens of Navicula major, which at one time extended 

 in separate pouches of the body posteriorly like the single one of fig. 5. 

 A Navicula was discharged, at the posterior extremity of the body, to one 

 side of the insertion of the caudal filaments and the contractile vesicle. 

 The latter measured 0.028 mm. in diameter. The nucleus in advance was 

 0.02 mm. diameter. 



Another specimen, with the body occupying a space of 0.26 mm. in 

 length by 0.2 mm. in width, had also but two caudal appendages. These, 

 when the animal was first seen, trailed backward from the side of a 

 mulberry-like mass formed of the posterior extremity of the body. The 

 measurements of the contractile vesicle and nucleus were the same as in 

 the former specimen. 



Fig. 9 represents a smaller specimen, resembling the former in the 

 possession of a pair of short caudal filaments which project in a widely 

 divergent manner laterally from the posterior mulberry-like termination of 



the body. 



Fio-s. 7, 8, are two views of an individual, a small specimen, with a 



to ' ' 



single pair of long caudal filaments. The contractile vesicle was distinct, 

 but there appeared to be no nucleus present, and the animal was also 

 devoid of visible food. 



OURAMCEBA BOTULICAUDA. 



Plate IX, figs. 13-17. 

 OuranuBia hotulieauda. Leidy: Proc. Acad. Nat. Sc. PhUa. 1875, 127. 



Species comparatively small, colorless, transparent, irregularly angular 

 in outline. Pseudopods short, conical, acute, rarely digitate. Caudal 

 appendages in one or two tufts, each composed of from two or three up to 



