RHIZOPODA AND HELIOZOA OF SCOTLAND 109 



submitted; and seeing, as I learn from Mr Evans, this does 

 not occur at all on either the Isle of May or on the Bass, 

 their Rhizopod fauna should prove particularly interesting, 

 as we shall be dealing with moss-dwellers as distinct from 

 sphagnum-dwellers. Sphagnum does, however, occur in St 

 Kilda, but was absent from the material examined, and 

 several typical sphagnum types of Rhizopod were present 

 in small numbers (e.g. y Nede/a tubiilata, Sphcnoderiafissirostris, 

 Placocysta jurassica). As previously pointed out, it is now 

 well known, thanks especially to the work of Greeff and of 

 Dr Penard, that certain species of Rhizopod occur in the drier 

 mosses, and not elsewhere ; and that these species are gener- 

 ally somewhat peculiar in structure in adaptation to their 

 comparatively dry habitat. Many of the species found in 

 these situations, however, also occur elsewhere, but they 

 frequently exhibit a less robust build and show more irregu- 

 larity of form in the drier habitat (see PI. V., Figs. 9 and 15) ; 

 while others again seem to reach their maximum develop- 

 ment in the ground mosses. This I believe to be true for 

 Spheuoderia dentata and Trinema enchelys. There always 

 occur in material of this type numbers of obscure and small 

 forms of Rhizopod life which are determined with great 

 difficulty, and as special attention does not seem to have 

 been given to them in this country, it is not surprising that 

 undescribed species should be found on careful search ; but 

 in the absence of a knowledge of their life-history, one feels 

 some doubts as to the advisability of adding new species to 

 the already lengthening list. It is only after continued 

 observation on large numbers of individuals obtained from 

 widely separated localities, that two new species are here 

 described. 



CORYCIA radiata, n. sp. (PI. V., Figs. 1-4).— This species 

 has the general characters of the genus, the protoplasmic 

 body being enclosed in a sac-like envelope or test, provided 

 with a widely open ventral aperture. It differs from C. 

 flava, apart from its small size, especially in the characters 

 of the dorsal region of the envelope. As in that species, the 

 test may be supposed to consist of two regions, an upper 

 or dorsal (posterior) portion, rigid, of fixed outline, formed 



