278 Mr. H. J. Carter on the Fresh- and Salt-water 



1859, and these abounded in a basin containing water from the 

 main drain of Bombay, which is flooded by the sea at each tide. 

 It is ahke remarkable for the eye-hke appearance imparted to it 

 by the nucleus, from which its specific name has been derived, 

 and for its gregarious habits. Stein considered that the whole 

 of the light-coloured granular zone, with its contents, constituted 

 the nucleus and nucleolus respectively. I am not certain that 

 the light-coloured zone may not be outside the nucleus, when 

 the inner circle and its contents would become the nucleus and 

 nucleolus respectively. Both appear to consist of fine granular 

 plasma. Stein, however, represents the whole together isolated 

 (I.e.) as the nucleus of ^. oculata, calling the light granular zone 

 the " Marksubstanz/' If the latter be within the nucleus, which 

 I think likely, then the nucleus in this state seems to indicate a 

 step towards generative development ; but in what the rest of 

 the process may consist, even if this be the case, remains for 

 future observation to show. 



The other peculiarity of this species, viz. its gregarious habits, 

 allies it to Spongilla, which is but an aggregation of amoebous 

 cells held together by a fine plasma. That o^ A. oculata appears 

 to be derived from the more subtle parts of their ectosarc, since 

 the Actinophryans thus aggregated are not in zygosis, as my 

 figures and Stein's will show, but merely held together in the 

 way described (figs. 1 & 2 6 6) ; while stomachal cavities are 

 extemporized in this ectosarc [c c c), in which fragments of 

 nutritious matter are enclosed, apparently for the use of the 

 whole community. 



This, too, seems to strengthen the view taken that the nucleus 

 is in a generative stage, when it may be advantageous for the 

 Actinophrys to have its interior freed from all extraneous 

 matter. 



Be this as it may, there are also other cavities in the ectosarc, 

 which contain large, smooth, subrotund, and nearly colourless 

 masses, apparently different in nature from the fragments of 

 crude food mentioned, being more like amylaceous concretions 

 than the latter; but whether these have been incepted, are the 

 remains of crude food, or what their real composition may be, I 

 am ignorant. They also equally characterize Stein's and my 

 own figures of this Actinophrys (figs. 1-3 dcld), 



I did not observe any specimens with contracting vesicles or 

 any other kind of vacuoles in a chain, round the Actinophryans 

 respectively, or in the uniting sarcode, as figured by Stein j but 

 the margins of the Actinophryans were defined by a strongly 

 marked crenulated line, indicating a corrugated superficial 

 layer. Nor have I in any of my sketches represented fragments 

 of crude food within the Actinophryans themselves. 



