EDMONDSON — PROTOZOA OF IOWA. I05 



like extension. This species presents some peculiarities in its 

 habit of movement, never seeming at ease unless it is clambering 

 around and around on a minute particle of plant tissue. When 

 it loses its hold upon its support it rolls and tumbles at random 

 through the water until it comes in contact with some other sup- 

 port. 



Reproduction is by transverse fission 



Order, PERITRICHA. 

 Family, VORTICELI^ID.^. 



GERDA C. & L. 



Elongate, cylindrical, highly contractile, not attached to but 

 resting upon some support. Oral aperture on the anterior bor- 

 der, eccentric, opening into a distinct pharynx. A series of strong 

 adoral cilia in a spiral fringe about the central, elevated, ciliary 

 disc, one extremity of the series descending into the oral opening. 



Gerda glans C. & E. 



Body about four times as long as broad when fully extended, 

 surface transversely striated. Pharynx greatly developed. Nu- 

 cleus band-like, longitudinally placed. Contractile vesicle pos- 

 terior, with canals directed anteriorly. 



Eength when extended, 150 microns. (Fig. 177, PI. XXV.) 

 Gerda glans has been found in one locality only in this state, in 

 Johnson county, among algae. The individuals are usually iso- 

 lated and rest upon the plant tissue for support, but are not 

 attached to it. Reproduction takes place by longitudinal division. 



SCYPHIDIA Dujardin. 



Elongate, cylindrical, contractile. Posterior extremity narrow, 

 with a suctorial border, by means of which it is attached to some 

 support. Surface smooth or furrowed. Oral system similar to 

 that of Gerda. 



SCYPHIDIA INCLINANS D'Udk. 



Body wider centrally, highly contractile. Ciliary disc elevated 

 obliquely, pharynx conspicuous. Surface smooth. 



On contraction the body is bent to one side and slightly short- 

 ened. 



Length when extended, 85 microns. (Figs. 178-179, PI. XXV. 



[Proc. D. a. S., Vol. XI.] 14 [June 9, 1906.I 



