FEOM NEW YORK, NEW JEESEYj AND GEOEGlA. 137 



Length 120-135 yu, ; diameter 74-80 //, ; neck about 30 /* diameter and 

 30-35 fjb in length. -Apertm-e 25-35 /x in diameter; collar 30-40 /a in 

 diameter. 



Habitat. Submerged sphagnum. 



Distribution. New Jersey. 



This species belongs to the group o£ which N. tenella and JS'. griseola are 

 the other members, but it exceeds them in size and is of quite distinctive 

 shape. The test is formed of angular plates mixed with a few circular 

 plates and diatoms ; it is of a dark colour/ more or less opaque, and is very 

 fragile. It is circular in transverse section. 



N. DENTISTOBIA, Penard. 

 Leidy, pi. 24. %. 12 (30). 



Typical individuals of this species occur only sparingly, and varied in 

 length from 90 //, to 110 [m, with a breadth equal to |-| of the length. No 

 circular or N. Jiabelhdiim-sivdTped tests were observed. 



Var. LACUSTRTS, var. nov. (PI. 12. fig. 10.) 



? N. collaris pars, Leidy, pi. 24. fig. 11 (30). 



Test large, pyriform, compressed, formed of angalar siliceous plates and 

 grains of various sizes ; with a small neck and aperture broadly oval. 



Length 120-206 /x ; breadth 100-143 jjl ; aperture 25-45 jju ; thickness 

 64-90 fji. 



Distribution. Lakehurst, N.J. ; Augusta, Ga. 



This variety exceeds in size every other of the numerous forms of this 

 species and appears to be a link with the large iV. vitrcea, Pen. sp. ver. ; its 

 size also distinguishes it from N. scotica, Brown (3. 1. 78-82 fi). 



The test illustrated by Leidy, pi. 24. fig. 11, taking as correct the given 

 magnification ( X 250), measures 208 /j, in length and 152 jx in breadth, which 

 nearly agrees with the Lakehurst specimens : the given measurement of 

 another, viz. length 100 /j,, breadth 68 fx, is very like H. scotica, Brown, but 

 the thickness given, 20 fi, seems improbable. 



N. equicalceus, Leid^ (31, 1874). 



W. hippocrepis, Leidy (30), pi. 24. fig. 13 ; pi. 25. figs. 9-14. 



This is a scarce species ; it is found in Penney\s Pond, Grood Ground. Leidy 

 illustrates two forms : one (pi. 25. figs. 9-14) provided with a solid carina 

 extending around the fundus, the other (pi. 24. fig. 13) without this carina ; 

 only the latter of these two forms was seen. The development of the internal 

 processes varied somewhat. 



Dimensions. Length 203-235 /x ; breadth 126-142 /z ; aperture 38-45 fi ; 

 thickness 72-80 fx. Length of horns when well developed 35-60 jjl. 



12* 



