79 



enveloped; and that the deviations from a perfectly spherical form 

 indicate different stages of the condition of the animalcule. I am 

 strengthened in this conjecture by several specimens in my collection, 

 in which part of the animalcule is quite free from the surrounding 

 mass, and the tentacula, which are almost always those of the species 

 ramosum (presently to be noticed), denuded of the substance with 

 which the other parts continue to be incumbered. Sometimes the 

 membrane seems to adhere to two or three tentacula separately, and 

 at other times to one only. This latter appearance suggests an 

 enquiry, whether the species we call crassipes, or thick-legged, is not 

 one of the vestita in progress towards a partial or entire separation 

 from its gelatinous accompaniment ; but I shall presently give my 

 reason for thinking it is not. Whether this substance surrounds any 

 of the other species I cannot say ; possibly it may, but those which I 

 have seen exclusively exhibit the tentacula which characterize Xanth. 

 ramosum. Its diameter measures from -^^ to ^|^ of an inch. 



The second species I call Xanthidium Jtmbriatum, or fringed, from 

 the short processes or stunted tentacula which densely surround the 

 body. I have not attempted to count the number ; indeed, I believe 

 it scai*cely practicable, in many instances, to count those round the 

 outer circumference, and therefore impossible in this, and in the other 

 species, to arrive at more than an approximation to the number of 

 tentacula which cover the whole surface of the bodies of these globu- 

 lar animalcules ; so that I have not attempted to make the number of 

 the tentacula a specific characteristic. It might be suggested that 

 these fringed processes are no more than the earlier indications of 

 those tentacula, which, in the more matured growth of the animalcule, 

 assume a much more lengthened appearance ; and may be the same, 

 in an early stage, as the hirsutum or furcatum afterwards mentioned. 

 But whether this be the fact I cannot say, as I have not found any in 

 such an intermediate state towards maturity as would support the 

 conjecture. Xanthidium jimbriatum measures in diameter from -j^ 

 to -j-^y of an inch. 



The third I call Xanthidium hirsutum, the name which has been 

 given to it by former observers, and, among others, by that accurate 

 observer, the Rev. J. B. Reade. It is so called from the hairy or fur- 

 red appearance which the numerous thin tentacula assume, being in 

 tufts, less uniform and regular in their arrangement than the next I 

 shall notice. It is not so perfectly spherical as most of the other spe- 

 cies ; indeed the uneven tufted or matted appearance of the tentacula, 

 like hair or fur, completely obscures the contour of the body on which 



