PLATE XLI. 



ACTINOSPH^EIUM EICHHORNII. 



Fig. 1. An individual, exhibiting a contractile vesicle at a, and the position, 6, at which another 

 has just collapsed. The large sphere e at the lower part of the figure is a vacuole containing a Eotifer 

 ■which has just been swallowed. In the interior, diatoms and other food materials may be seen. 250 

 diameters. China Lake, Uinta Mountains, Wyoming, August, 1877. Abundant at the locality. 



Fig. 2. Individual with comparatively few and short rays, a, contractile vesicle ; 6, position at 

 which one has just collapsed ; c, large vacuole containing a Kotifer in the act of being swallowed ; d, 

 act of discharging effete matter. 250 diameters. Ditches below Philadelphia, with Lemna, Wolffia, 

 etc., fcequent, April, 1877. 



Fig. 3. A small individual with long rays. 250 diameters. Lake. Hattacawanna, Morris County, 

 New Jersey, March, 1875. a, contractile vesicles. 



Fig. 4. Individual with only five rays. Shortly after being noticed other rays were produced, 

 and in an hour subsequently numerous rays extended in all directions, a, contractile vesicle ; c, food 

 in the act of being swallowed. 200 diameters. Pond in Fairmount, Philadelphia, September, 1875. 



Fig. 5. Small individual with few rays, a, large contractile vesicle. 250 diameters. Ditches 

 below Philadelphia, September, 1875. 



Fig. 6. A remarkable rayless individual, containing a Eotifer and other food materials, which 

 were subsequently discharged, when the animaj assumed a more regular spherical form. 200 diameters. 

 Found with the preceding. 



Fig. 7. Portion of an individual magnified 1,000 diameters, a, contractile vesicle; 6, nucleus. 



Fig. 8. An unknown Heliozoan, suspected to pertain to Actinosphserlum. 500 diameters. Marsh 

 at Bristol, Pa., August, 1876. 



Figs. 9, 10. Anomalous body, suspected to be a detached portion of an Actinosphserium. 500 

 diameters. Ditches below Philadelphia, April, 1876. 



Fig. 11. Areolated body, suspected to be a moult of an Actinosphserium. 100 diameters, Abse- 

 com pond, New Jersey, March, 1876. Similar bodies occasionally found and suspected to be related with 

 Actinosphaerium. Perhaps it is entirely foreign to the latter and may be a vegetable product. Fig. 13i 

 A portion of the same magnified 200 diameters. 



