PLATE XIV. 



DIFFLUGIA UECEOLATA. 



All tlie figures were taken from living specimens, represented in t'aeir usual iiosition, and willi 

 tte shells composed of angular particles of quartz sand. 



Fig. 1. Variety approaching Difflugia acuminata. 200 diameters. Swarthmore hrick-pond, Dela- 

 ware County, Pennsylvania, October, 1875. 



Fig. 2. Variety with less acuminate fundus to the shell. 250 diameters. Lake of Uinta Mount- 

 ains, Wyoming, August, 1877. 



Fig. 3. Variety Difflugia amphora. 100 diameters. Ditch below Philadelphia. Common form. 



Fig. 4. Oral view of a similar specimen. 



Fig. 5. Characteristic specimen of Difflugia ureeolata. 200 diameters. Absccom pond, New Jersey, 

 August, 1876. Common form. 



Fig. 6. Narrower variety of the same kind occurring with it. 



Fig. 7. Common form in ditches communicating with the Delaware River below Philadelphia. 



Fig. 8. Common form ; abundant in a pond of Bridger Butte, Fort Bridger, Wyoming, August, 

 1877. 250 diameters. 



Fig. 9. Acuminate variety, with additional spines to the fundus. A not unfrequent form. Atco, 

 N. J., September, 1877. 250 diameters. 



Fig. 10. Common variety. Absecom pond. New Jersey. 250 diameters. 



Fig. 11. Variety named Difflugia olln. Abundant in the ponds of sphagnous swamps. Budd's 

 Lake, Now Jersey, September, 1874. 250 diameters. The sarcode encysted. 



Fig. 12. Unsymmetrical specimen. Absecom pond, New Jersey, September, 1875. 200 diameters. 



Fig. 13. Many-spined specimen, found with the former. 200 diameters. Each spine ending in a 

 single large sand grain. 



Fig. 14. Single-spined specimen. Atco, N. J., September, 1877. 250 diameters. The spine end- 

 ing in a single large sand grain. 



