182 



cordiform, sinus widely open, lateral margins convex, apex in- 



curved. Vertical view elliptic, ratio of axes 1-1,3. Cell-wall smooth. 



Size: long, g {x, lat. j,s (x, lai. isthni. 2,j [i, crass. 4,8 [x. 



This Cosmarium is quite distinct, though closely related to 

 Spondylosiwn secedens (De Bary) Archer, but filiform conditions 

 were not observed. The isthmus is considerably narrower, and 

 the general ondine is also rather different. 



(Maja was the Roman name of Merano, possibly derived 

 from the goddess represented by the month of May). 



27. Cosmarium margaritiferum Menegh. 



Meneghini ; Synoposis Desm. 



This Desmid occurred very abundantly. The specimens were 

 closely related to some forms of Cosmarium praemorsum. There 

 is, no doubt, a whole range of intermediate forms between the 

 two species, but on the other band, the characters pointed out 

 by Messrs- West in British Desmidiaceae, Voi. Ili render a spe- 

 cifìc separation quite justified. 



1. a. Se ò. Cosmarium Majae ca. 1000 X {b. vertical view.) 



2. Cosmarium obsoletum ca. 750 X 



28. Cosmarium obsoletum (Hantzsch) Reinsch. 



Hantzsch in Rabenhorst : Alg., Reinsch : Spec. Gener. Alg. 



This Desmid, which is chiefly a tropical, and subtropical spe- 

 cies, occurred in immense quantities. In size the specimens were 

 more inclining towards the northern forms than towards the 

 strictly tropical ones. The pores in the papillae were, however, 

 distinct in some specimens, such as in that figured. 



Size : long. 44 [x, lat. 48 |x, lat. istm. 18 p.. 



