HALIPHYSEMA. 35 



Professor Hacckel next entered in the field, and 

 published an elaborate essay illustrated with a number 

 of plates. He apparently proved to demonstration 

 that Haliphysema could be nothing else than a sponge, 

 and he assigned it to that position, and as one of the 

 simplest forms of the Coelenterata. He described and 

 figured Haliphysema as having a hollow interior every- 

 where lined with the " flagellated cells " or " collar- 

 bearing monads" characteristic of sponges; furnished, 

 moreover, with a curious single spiral line of such 

 flagellated cells of much greater size than the rest, 

 while at the bottom of the cavity he described and 

 figured ovate objects which were regarded as eggs. 

 No cne at this time could have reasonably supposed 

 anything else than that Haeckel had clearly proved 

 Haliphysema to be a low type of sponge. 



Meanwhile I had myself procured certain organisms 

 from my own dredgings off Valentia and from material 

 brought up the " Porcupine " from considerable depths 

 in the Atlantic. These appeared to me, on the one 

 hand, so nearly to resemble Haliphysema that they 

 could scarcely belong to a different class, and, on the 

 other, so closely approaching many of the Lituolidan 

 Foraminifera that no line of demarcation seemed pos- 

 sible. In a paper in the ' Annals ' I summarised what 

 was known and had been written respecting Haliphy- 

 sema retaining its place, in consequence of Haeckel's 

 apparently conclusive proofs among the sponges, but 

 criticising the genera and species which he had insti- 

 tuted. In this paper I described the allied organisms 

 under the names Technitella and Marsipella as "genera 

 incertce sedis." I did not dare to separate them from 

 the Foraminifera to which they appeared to me to be 



