at the posterior end. Several of the pelomyxas also move in much the same manner as _Amoeba laureata_, that is, in clavate form and more or less cylindrical in shape. This is especially the case with _Pelomyxa palustris_ and _P. belevskii_. But in these species the endoplasm is not completely converted into ectoplasm at the anterior end, as is shown by the fact that there is a slight backward current of endoplasm at the sides near the anterior end (Schultze, ’75). Observation indicates also that the ectoplasmic tube is thinner than would be the case were there complete transformation of endoplasm into ectoplasm at the anterior end. The origin of pseudopods in these pelomyxas is not steady and under control as in _laureata_, but sudden and eruptive, indicating a less coherent ectoplasm. The nearest approach to the conditions of streaming as found in _Amoeba laureata_ is found in _A. discoides_ (Figure 11, _B_) a species often confounded with _proteus_. This species is frequently found in clavate form, and the conversion of endoplasm into ectoplasm is complete at the anterior end. In other respects of streaming and pseudopod formation, the two species are also similar. In another very common species of ameba, _Amoeba dubia_ (Figure 11, _C_) the clavate stage of locomotion is comparatively rare, but when it is found it is observed that the transformation of endoplasm into ectoplasm at the anterior end is incomplete, and the endoplasm seems to be of very liquid consistency. This ameba is characterized by the possession, usually, of numerous pseudopods extending from a central mass of protoplasm. In this stage it possesses no _main_ pseudopod as does _proteus_, _discoides_, _laureata_ and other species, but there are three or four pseudopods extending actively in the general direction of locomotion. The physical characteristics of these pseudopods, in so far as streaming is affected, are different from those of the clavate amebas. The ectoplasmic tubes are relatively thicker, the endoplasm is less fluid, and new pseudopods are not formed so readily. It appears therefore that an increase of surface in the ameba serves to increase the amount of ectoplasm that is formed during locomotion. [Illustration: Figure 5. _Amoeba limicola_, after Penard. Figures _a_, _b_, _e_, illustrate the “eruptive pseudopods” by means of which this ameba moves. _f_, a variety or separate species whose ectoplasm is somewhat firmer, and whose posterior end possesses a conspicuous uroid. _c_, the nucleus found in _a_, _b_, _e_. _d_, the nucleus found in _f_.]