162 PROCEEDINVS OF THE ACADEMY OF [PaRT I 



was found, rather numerous, in two different localities: Pinchat, 

 where I found it in every season of the year, and Rouelbeau, where 

 it was seen on one occasion only. 



The most striking quality of this Flagellate is perhaps found 

 in its special coloration, a beautiful bright green, which invests 

 the whole body, and at once distinguishes it from the many other 

 colored organisms that are svvimming about. It is the pure green 

 of chlorophyll, such as is found in the spherical granules of the 

 higher plants, being without admixture of blue or brown. 



The body (Plate VIII, fig. 64), measuring 40, 50, and up to OOfx 

 and more, is in the form of a fish, two to three times as long as broad, 

 somewhat compressed laterally, broader at the anterior end, nar- 

 rower posteriorly, and often terminating in a point. The form 

 of the whole body is slightly changeable, subject to alteration here 

 or there, becoming now and then contorted or even excavated, 

 but coming after a time to its original shape. The little green 

 organism goes straight on its way, with a single flagellum visible, 

 which is thin and straight, about as long as the body, and which 

 hardly seems to move. From time to time, a sudden advance or 

 leap is noticed, somewhat as in Cryptomonas but to a much shorter 

 distance, and not always backwards but forwards just as well. 

 To get an adequate understanding of the intimate structure of 

 Trentonia, it is necessary to have recourse to compression, gentle, 

 weak enough not to deform the body to more than a moderate de- 

 gree, and yet strong enough to stop its movements (Plate VIII, 

 fig. 65). The result required is, however, easily obtained, as the 

 periplast is absent (or rather represented by a very thin hardened 

 pellicula) and nothing prevents the body expanding. The body, 

 in fact, may be considered as naked, so much so that with a stronger 

 compression the animalcule is seen to transform into the shape of 

 an A'moeba, displaying lobes or even extending into pseudopodia. 

 Inside the very thin surface pellicle is a rather thick layer of very 

 pure ectoplasm, of a peculiar appearance, opalescent and shining, 

 and in it are seen dispersed a number of very small light vesicle, 

 or vacuoles, which seem to be provided with a distinct wall. But 

 in that external opalescent layer other elements are found, tiny 

 spherical granules, very clear and brilliant, which often are seen 

 to protrude over the surface of the pellicula, sometimes even in 

 the shape of short setae. ^^ They must probabh^ be considered 

 as trichocysts, the very structures which are represented by Stein 

 in Rhaphidomonas semen as rod-like in form, but in the present 

 species globular. Inside this ectoplasmic layer are the chromato- 



^^ In an animalcule that had been much compressed, along its longitudinal 

 axis (Plate VIII, fig. 66), without any addition of a reagent, the whole surface 

 was seen surroimded by very short radial filaments, which must have resulted 

 from thn exploding of these tiny bodies. 



