272 Dr. A. Gruber on Protozoa. 



tern, I must admit that I am not in a position to range it with 

 any previously known form. In the formation of the pseudo- 

 podia it has perhaps the greatest resemblance to Orbulinella. 

 As regards the peculiar envelope consisting of fine bacilli, I 

 can indicate no analogue of this. The only thing that has 

 struck me is its resemblance to the coating of fine processes 

 which Archer* has described in his D laphoropodon mobile; 

 but in the latter form the little rays are pseudopodia, and not 



rigid bacilli. 



The completely closed envelope, traversed by pores, indi- 

 cates a distant resemblance to the Perforata among the Fora- 

 miiiifera ; while its want of consistence and the form of the 

 seudopodia, as well as the whole structure of the protoplasmic 

 ody, rather refer Pachymyxa to the amoebiform Rhizopods. 

 Together with the form that I have just described, there was 

 also in the marine aquarium at the same place a number of 

 naked masses of protoplasm, varying in size between about 

 the dimensions which I have given above for Pachymyxa. 

 These creatures, with regard to which I will hereafter endea- 

 vour to decide whether they are identical with Pachymyxa or 

 not, show many interesting pecularities j so that I must give 

 a detailed description of them. 



In these also the protoplasm is characterized by its tenacity 

 and density, so that none but extremely slow, scarcely visible, 

 phenomena of motion are exhibited by it. These Rhizopoda 

 are consequently'also very opaque, especially if, as is fre- 

 quently the case, they are tilled with large brown food-masses. 

 Very frequently such nutritive constituents are enclosed in the 

 interior of a special large vacuole or digestive cavity, sharply 

 marked off from the surrounding parts. At other times the 

 balls lie scattered through the inner parenchyma of the body. 

 In general the external appearance of the individual speci- 

 mens may be exceedingly different, as the protoplasm may at 

 one time acquire an entirely granular texture, and at another 

 a vesicular ^consistency full of vacuoles, and lastly appear 

 hyaline and transparent. Very frequently a division into an 

 external clear layer of protoplasm and an endoplasm filled 

 with nutritive constituents may occur, the latter then repre- 

 senting a sort of nutritive paste. Such specimens (fig. 4) 

 show a very regularly vacuolar exoplasm, from which the 

 pseudopodia issue. The outer layer here exactly resembles 

 that of an Actinophrys sol. Within it the endoplasm, coloured 

 brown by the nutritive paste, is seen sharply differentiated. 



* Quart. Journ. Micr. Soc. new ser. ix. ; see also Blitschli, in Bronns 

 KI. und Ordn. des Thierr. Taf. it. ii£. 1. 





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