136 ME. G. H. WAILES OlSr FEESHWATER EHIZOPODA 



Length 80-84 //, ; breadth 60-68 jx ; aperture 20 /x. Spines 4 or 3 in 

 number and 16-20 fx in length. 



Nucleus about 12 yu- in diameter with a large nucleole. 



Distribution. Long Island, N.Y. ; Ahsecom, N.J. (Leidy) ; Nantucket 

 Isl, Mass. (18) j Ohio (28); British Columbia (39) ; Scotland (Mtrra?/) ; He 

 Macquarie (39) ; New Zealand (39) ; Australia (39) ; Gough Isl. {Peaard). 



Nebela caeinata (Archer), Leidy. 

 Leidy, pL 24. figs. 1-5, 9, 10. 



Often numerous in submerged sphagnum. 



Length 200-260 /z ; breadth 135-160 jx ; aperture 30-40 yu, ; thickness 

 63-73 ix. 



t 

 N. coLLARis (Elirenb.), Leidy. 



Leidy, pi. 22. figs. 1-10, 13-15, 17-20 (30). 



Not abundant ; length 100-130 [x. 



Var. EETOETA, Leidy. (PI. 12. figs. 6 & 7.) 

 Leidy, pp. 151, 289, fig. p. 151 (30). 



Tests answering to Leidy's description and drawing are not uncommon in 

 Penney's Pond, Good Ground, the only locality in which I found them. 

 They are not merely curved tests but are modified to such an extent as to 

 veil the specific characteristics. The curvature takes place in the plane of 

 the greatest width and is generally greater than in Leidy's drawing (p. 151) ; 

 in narrow view there is no curvature and the tests are compressed. The 

 aperture, which is not notched, loses its smooth outline and is bordered by 

 circular or oval plates. 



Accompanying the Nebela: was a similar form which could without 

 hesitation be referred to Quadrida symmetrica, the typical form of which is 

 numerous there. Two species of Nebela seem to be thus modified, viz. 

 N. collaris and iV^. americana, and the latter in its typical form is much the 

 more numerous. The occurrence tooether. in fair numbers and in a sinole 

 limited habitat, of these special forms seems to indicate that local conditions 

 have a controlling influence in their formation and that they are not auto- 

 nomous species but sporadic varieties locally induced. 



Length 130-170 fx ; breadth 52-97 fx ; aperture 26-39 fx. Leidy observed 

 a single individual only, length 144 fi. 



N. CEATEEA, sp. UOV. (PI. 12. figs. 8 & 9.) 



Test of moderate size, not compressed, pyriform, neck small and parallel; 

 aperture bordered by a prominent collar semicircular in section. Plasma 

 and pseudopodia normal. 



