44 CONNECTICUT GEOL. AND NAT. HIST. SURVEY. [Bull. 



formly ciliate, but with longer cilia at the anterior end. 

 One terminal contractile vacuole. Nucleus divided into 

 small pieces. 

 Ch. teres Duj., Fig. 140. This is the only species described, 

 but I have found several other forms that apparently must 

 be classed under this genus. Figs. 138 and 139 represent 

 two of these forms. Fig. 141 is perhaps a small specimen 

 of Ch. teres. Fig. 142 represents a very common animal 

 whose relations have appeared doubtful to me. I place 

 them in this genus provisionally, although they may be 

 young forms of some other genus. 

 Enchelys Ehrbg. 



Differing from Holophyra chiefly in having an ob- 

 liquely truncated neck-like prolongation with the mouth 

 slightly on one side. No pharynx, a terminal anus, and 

 a uniform ciliation. Nucleus spherical to ellipsoidal. 



Enchelys is another genus that presents great difficulty 

 in specific determination, and is frequently hardly dis- 

 tinguishable from Holophyra. Fig. 128 I regard as, per- 

 haps. En. pupa, Ehrbg., while Figs. 124, 125, 126, and 

 134 are, with hesitation, placed in this genus, the evident 

 lateral mouth apparently excluding them from Holophyra. 

 More study is required before the limits of these two 

 genera can be drawn. 

 Spathidium Duj. 



Elongated, sac-shaped, flexible, with anterior end nar- 

 rowed and flattened into a neck which is obliquely trun- 

 cate. The mouth occupies the whole of the oblique sur- 

 face and is usually surrounded by lips and closed. 

 Pharynx sometimes with rods. Uniform ciliation, ter- 

 minal vacuole, nucleus elongated and bead-like. 



Spathidium is difficult to distinguish from Enchelys. 

 Fig. 128, which I have called Enchelys, shows such an 

 elongated neck as to suggest that it may be classed with 

 Spathidium. Figs. 129 and 131 are clearly the latter 

 genus. 

 S.sp. (?),Fig. 129. 

 S. spathida (?) Duj., Fig. 131. 



