EUASTRUM. 101 



The following varieties deserve a separate note: 

 Var. <i;i \ A ikkaxwk, Wolle. Plate XXVI, fig. 2. 



More angular, and more distended in the lobes, gives this 

 form a strong resemblance to an African MicraMerias, de- 

 scribed by Cohn, and suggests the name. 

 Pond, eastern Pennsylvania. 



Var. AlLATUM, Wolle. Fig. I. Very Dear Corda'a Coamariwm 

 (datum. 

 Marsh pools Dear Minneapolis, Minn., and Bucks Co., Pa. 



Var. REDUcn i m, Nbrd. Fig. "-. 



This specimen does doI agree as well as many others found 

 in the same locality and group. I therefore add a translation 

 of the author's diagnosis from his / >< Algis Musei T/ugdv/no- 

 Batavi: 



'Sinn- between the semicells linear; sides and angles close; 

 end lobe scarcely dilated, apes retuse, middle lobe small ; end 

 view rectangular ; tumor in the middle of the semicell obovate 

 elliptic, others very small." 



E. circulare, (Hass.) Ralfs. Plate XXVIII, figs. L, 2. 



Semicells three Lobed, mostly with five basal tubercles; end 

 notched, scarcely dilated. 



Ralfs make- three varieties; a. semicells inflated a1 the base 

 an<l attenuated upwards; b. semicells emarginate at the -ides, 

 the basal portion with Ji\ < tubercles; c. emarginate at the 

 sides; tubercleB smaller, more numerous and scattered. 



Diameter 36 >'... more or less. 



Rhode Island, New Jersey, Pennsylvania; common. 



E. GEMMATUM, P>rel>. Plate XXVIII, figs. ">, 4. 



About one-half longer than broad; semicells three lobed, 

 lateral lobes horizontal, deeply emarginate; the protuberances 

 minutely granulate; terminal lobe dilated, broadly emarginate; 

 transverse view broadly elliptic, with three granulate inflations 

 on each side (not four, as incorrectly drawn) and one at each 

 end ; end view shows the terminal lobe, cruciform. 



Diameter 38 u. 



Found from Rhode Island to Minnesota, ami southward. 



