204 FRESH-WATER EHIZOPODS OP NORTH AMERICA. 



below it there is an accumulation of oil-like molecules. Between the 

 latter and the mouth of the shell, the sarcode contains variable propor- 

 tions of food materials, water vacuoles, and commonly several contractile 

 vesicles. 



The pseudopods radiate from the mouth, often to a distance consider- 

 ably more than the length of the shell. They are exceedingly delicate, 

 and branch usually at very acute angles, but do not anastomose. Some- 

 times, in movement, they abruptly bend, and occasionally suddenly con- 

 tract in a tortuous manner. 



Ordinarily, the shell of Cyphoderia measures about 0.125 mm. in length 

 by 0.05 mm. in breadth, but specimens range from about 0.11 mm. to 0.2 

 mm. in length. 



Cyplwderia ampulla is common in the ooze of springs, ponds, and lakes, 

 though I have never found it very abundantly at any one time. I have 

 obtained it from springs and ponds in the vicinity of Philadelphia. The 

 largest specimens I found at Lake Hattacawanna, New Jersey. I also 

 found it in China Lake, in the Uinta Mountains, at an altitude of 10,000 

 feet, and likewise at the base of the mountains, at Fort Bridger, in Wyoming 

 Territory. The Wyoming specimens were remarkable from their commonly 

 having the shell with a nipple-shaped prolongation at the fundus. 



The genus Cyphoderia was characterized by Schlumberger in 1845, 

 and the species described under the name of Cyphoderia margaritacea from 

 specimens obtained in the mud of brooks of the Vosges and Jura. The 

 same was, however, described by Ehrenberg, five years earlier, in the 

 'Bericht' of the Academy of Sciences of Berlin, under the name of Difflugia 

 ampulla* This is confirmed by figures of the species published in the 

 'Abhandlungen' of the same society in 1871. Recent authorities adopt the 

 specific name of Schlumberger ; but there is no good reason for retaining 

 it, and, according to the usual rule, I have employed the earlier name. 



CAMPASCUS. 



Greek, kampe, bent ; askos, a bottle. 



Animal provided with a shell having the form like that of Cyphoderia, 

 but provided with a pair of lateral divergent processes to the fundus, and 

 composed of homogeneous chitinoid membrane. The soft part together 

 with pseudopods as in Cyphoderia. 



"The original description is as follows: " Lorica oblonga clavata, punctorum seriebus obliquis 

 eleganter notata, hyalina, ostiolo ovato. Mag. ^'"." 



