36(5 MK. J. 31. BROAVN OX FRESHWATER RHIZOPODS 



EuGLYPHA COMPRESSA, Carter, in '•Annals 4" Mag. of 2^at. Hist.,' i]rd ser., 

 xiii. & XV. ; Penard, ' Faune rlvizopodiqxie ^t.,' p. 507. (PLite 50. figs. 11 

 & 12.) 



Besides the features characterising this species, i. e. the very compressed 

 nature of the test and the form of the plates, the presence of spines of special 

 form is of interest. These spines are particularly long and prominent, 

 averaging- about 20 /a in length. The}' arise from the intervals between con- 

 secutive plates around the lateral margin of the fundus of the test. Each 

 has the shape of a flattened blade tapering towards the free extremity, and 

 narrowing more suddenly towards the base, where it enlarges abruptly to 

 form the button-like structure by which it is held to the test. They arise 

 generally in groups of two or three. They are quite different from the 

 spines of E. alveolata, in which species they arise as outgrowths of the plates 

 themselves, and also from the " cilia "" of E. ciliata. 



One example from Easedale Tarn was of particular interest. It appeared 

 to be in the stage preparatory to division. The protoplasm contained many 

 plates ready for the formation of the daughter test, and these were, at any 

 rate in part, arranged definitely in position with reference to their relative 

 places in the new test. This was especially seen in the toothed plates which 

 surround the " mouth. '^ Ten toothed plates, five above and five below, were 

 seen lying side by side near the end of the fundus. Beyond these, ordinary 

 oval plates were visible, alternating with them ; while lying between them 

 were the large spines with pointed ends towards the mouth of the old test. 

 It thus appears as if the plates and spines for the new test are to some 

 extent arranged before the daughter protoplasm passes out from the old test. 

 Unfortunately the process of division did not seem to be completed. 



Placocysta spinosa ( Carter) ; Leidy, ' Freshwater Rliizopods of N. America' 

 p. 221. 



This species is very characteristic and is readily distinguished from the 

 Eiiglyplias by the absence of teeth on the plates surrounding the mouth. The 

 spines, however, are very similar in character to those of Euglypha compi^essa. 

 It seems to be rarely met with, although it is also recorded by Prof. G. S. 

 West from Bowness (Westmorland) and from Hawkshead (Lancashire) in 

 this district. 



Size : length 145 fi, breadth 100 fj,. 



Trinema lineare, Penard, in ' Mem. Soc. phys. et hist. nat. Geneve,'' 1890; 

 & ' Faune rhtzopodique Sfc.,' p. 529. 



This form appears quite distinct from T. enchelys. It is uniformly longer 

 and narrower in proportion and more tube-like, with the mouth obliquely 

 placed across the narrower end, and not so distinctly ventral as in T. enchelys. 



Size : up to 25 /* x 9 /x. 



