EU A STRUM. 115 



E. EROSUM, Lund. 



Very near the preceding ; in front view barely separable. 

 End lobe usually rather wider, and not so deeply incised; 

 notch obtuse-angled. End and lateral views somewhat quad- 

 rangular with ends imperfectly tricrenate. 



E. INSULARE, Witt. 



This form the author gives as a variety of E. binale. I 

 prefer it separated because the basal lobes are emarginate, 

 corresponding with the preceding two. It is distinguished 

 by a greater breadth of the terminal lobe and the absence 

 of an incision or notch ; sometimes slightly sinuate. Size 

 rather less. 



E. INERME, Lund. Plate XXXIII, figs. 6-8 ; Plate XXXI, figs. 



30, 36. 



Subelliptic; semi-cells subtriangular, apex somewhat pro- 

 tracted, truncate, deeply incised, not dilated or dentate; 

 sides biundulate, the basal crenae most prominent, obtuse, 

 and angle obliquely truncate; tumors three, inconspicuous 

 and sometimes wanting ; end view subelliptic, sides bigib- 

 bous ; side view ovate. Membrane finely punctate. 

 Diameter 32-38 yu. 

 Rather common. 



E. CRASSICOLLE, Lund. Plate XXXI, figs. 37, 38. 



About twice as long as wide ; sinus narrow linear ; semi- 

 cells slightly attenuated, three lobed ; lateral lobes, lightly 

 sinuate-bilobulate ; polar lobe broad, barely dilated, apex 

 emarginate ; end view hexagonal, poles truncate, middle 

 inflated. 



Diameter 14 //. ; length 28 /*. 

 New Jersey not frequent. 



E. CUSPIDATUM, Wolle. Plate XXXI, fig. 32. 



Diameter slightly less than length ; semi-cells distinctly 

 three lobed, basal lobes extending laterally their own width ; 

 end lobe subrectangular, twice the width of the other lobes, 

 obtusely sinuate in the center ; ends of the rounded basal 

 lobes and of the two sections of the end lobe, surmounted 

 each with three firm, diverging aculei. 

 Diameter without aculei 25 ^. ; with them 33 /^. 

 Pond, Absecom, N. J. Coll., H. D. Kitchel, 1882. 



