GENUS DINAMCEBA— DINAMCEBA MIEABILIS. 91 



ules of the endosarc enter ; posteriorly finely papillate, or with a discoid 

 papillate subdivision. Exterior of the body colorless and transparent; 

 interior yellowish and spotted brown or green fr<jm the food contents. 

 When moving, the animal resembles a sea-slug, Eolis, in its shape and from 

 its many long pointed pseudopods. At the fore part of the body, in pro- 

 gression, a large extent of perfectly clear ectosarc precedes the endosarc, 

 equal to about one-sixth of the length of the body. This is blunt in front, 

 and with its divergent pseudopods resembles the head of a slug. When 

 floating, the animal looks like a large Actinophrys with thick conical rays. 



This amoeboid, which I now suspect to represent only another condition 

 or stage of Dinamceba mirabilis, I have repeatedly found, in the autumn, in 

 the same localities. It agrees in habitual shape and size, in the kind of 

 pseudopods, and the possession of the posterior papillary organ, with the 

 more characteristic form. We have seen that both the minutely spiculate 

 condition of the surface and the gelatinoid coat of Dinamceba may be dis- 

 pensed with, so as to reduce it to the condition of the amoeboid form under 

 consideration. 



This amoeboid seems as if it were Dinamceba which had passed the 

 actively feeding stage, as it contains but comparatively little food and the 

 endosarc is much reduced. The large proportion of ectosarc in relation 

 with the endosarc reminds one of Amoeba verrucosa. 



In motion, the creature advances slug-like in manner and general 

 appearance. The body is composed of a central mass of granular endo- 

 sarc enveloped with a thick layer of clear ectosarc, of which a still thicker 

 portion forms the head, as seen in figs. 5, 7, and 10, pi. VII. The pseudo- 

 pods, usually numerous, form subulate processes of clear ectosarc occu- 

 pying mostly the anterior region of the body. The posterior papilla? are 

 variable in number and size, and in advance show more or less disposition 

 to merge into pseudopods. 



Figs. 5-7 represent three successive views of the same individual as 

 observed at intervals during thirty-six hours. As first seen, fig. 5, it was 

 elongated elliptical with prolonged blunt poles, both of which, as well as 

 the exterior layer of the intermediate body portion, appeared to be com- 

 posed of clear ectosarc. The central mass of granular endosarc was 

 mingled with diffused brownish material, and contained a few clear globules 

 or vacuoles, various articles of food, and a large pale granular nucleus 



