INFUSORIA FROM BRISTOL. 137 



The pharynx of Bicolor is very large, and terminates in a tubu- 

 lar oesophagus, which extends down to the coloured part of the 

 lorica. 



The animal is quite colourless; inside the lorica a constant 

 cyclosis of large granules may often be seen. I have seen no 

 traces of a fringe round the lorica. In one case the lorica, when 

 first seen, contained a second zooid, contracted, and not reaching 

 to the neck ; this one soon emerged from the opening and swam 

 away. Amongst specimens of this species, I came across one 

 which may possibly be a different species (Figs. 8 and 9). The 

 lorica was yellow, oval, and rather more than i-^ times as long as 

 broad. The anterior margin of the lorica was at right angles to 

 the surface of attachment, or nearly so ; its upper margin forming 

 an everted rim. Seen from above, the opening was large, oblong, 

 and oblique, the right side not raised at all, the left side produced 

 so as to form a kind of ear. This peculiarity separates it from all 

 other species of the genus. There was no frill-like expansion 

 round the lorica. Two zooids inhabited the lorica ; they were 

 hyaline, the body thick, and protruding for some distance outward 

 and forward. The peristome thick, and the ciliary disc a good deal 

 elevated. I did not notice any hood, but my attention had not 

 then been drawn to its existence in Bicolor. The animals extended 

 themselves readily, but were also fond of remaining with their 

 heads just filling the mouth of the lorica. Length of lorica, 

 i-333rd inch. If it is really a new species, I should propose to 

 call it Platycola aurita. Its nearest ally seems to be P. regularis 

 (De Fromentel). 



P.S. — Since the above description of Pyxicola anmilata was 

 written, I find that Dr. Leidy discovered the same animal appar- 

 ently on the other side of the Atlantic, just about the same time, 

 and gave it the same name. This is a curious coincidence. 



EXPLANATION OF PLATE XV. 



Fig. 1. — Zoothamnium Kcntii. 

 ,, 2. — The same, a single zooid; e., endoplast ; c.i'., contractile 

 vesicle. 



