52 PROCEEDINGS OF THE ACADEMY OF [1884. 



In appearance, the form now to be described is markedly convex 

 on the dorsal side, but is deeply indented longitudinally on the 

 ventral side. The sarcode is highly vacuolate, the vacuoles nar- 

 rowing towards the centre of the body. The fluid sarcode is 

 granular, and the surface of the body is covered with a network of 

 circles of various sizes, which, when enlarged three hundred 

 and fifty diameters, are seen to be minute globular vacuoles. 

 The snout-like prolongation, at the base of which is situated the 

 oral aperture, is shorter than is usually represented in Trachelius 

 ovum. 



The principal difference has regard to shape, Trachelius ovum, 

 being egg-shaped, as indicated by the name, while the form just 

 described is globosely convex dorsally, but flattened with a deep 

 indentation A'entrall3\ 



It is a curious fact, and one whose import is not very compli- 

 mentar}'^ to our water-supply, that the habitat of Trachelius is 

 universally given as bog-water. 



It is proposed to name this new species Trachelius Leidyi'm 



The following was ordered to be printed : — • 



