MICRASTERIAS. 125 



section em a ruinate, mucronate at each angle; polar lobe 

 prominent, widely dilated, center notched, margins mu- 

 cronate. 

 Diameter 175-200 //. 



Ponds, Pennsylvania, New Jersey and Minnesota ; rather 



rare. 







M. MAMILLATA, Turner. Plate XLVI, fig. 2. 



Semi-cells papilionaceous, five lobed; end lobe broad; its 

 ends and those of the other lobes divided into palmate 

 shapes, with the points broadly rounded ; surface adorned 

 with mamilliform processes radiately arranged; provided 

 with a process at isthmus, the purpose of which is appa- 

 rently (!) to strengthen the segmental union. Only one 

 specimen (semi-cell) seen. Seemingly related to M. aplculata. 

 Diameter 198 ^. 



Inasmuch as this semi-cell was found in collections made 

 in a swampy part of Harvey Lake, Pennsylvania, in which 

 M. apiculata occurs freely, the author would emphasize the 

 last remark. 



M. ALATA, Wall. Plate XLVI, fig. 1. 



In anticipation of the possible discovery of this interest- 

 ing and unique form in Southern Florida, I quote it from 

 G. von Lagerheim's Bidrag till Amerikas Desmidie flora. It is 

 an Indian plant, but is now also found in Cuba. The figure 

 is drawn direct from an India specimen in my herbarium. 



M. NORDSTEDTIANA. Wolle. Plate LXII1, figs. 3-5. 



Cells of equal length and breadth, smooth; semi-cells three 

 lobed ; the lateral lobes divided into two subcylindrical seg- 

 ments with a wide notch between ; ends obtuse, furnished 

 with thivo or lour small spines. Polar lobe exserted on a 

 long neck having a short conical prominence about the 

 middle of each side ; the ends diverge in two pair composed 

 of one longer and one shorter, nearly horizontal, arms ; the 

 two are nearly parallel. 

 Diameter 150 //. 



Longwood Pond, Passaic County, N. J., and Harvey Lake, 

 Luzerne County, Pa. 



This species has a number of distinct features; the four 

 arms of the end lobe ; the protuberances of the neck ; the 

 lateral lobes have something in common with M. ringem, but 

 they are smooth or finely punctate, not granulate ; there is 

 something also to remind one of M. pseudofurcata, but the 

 arms are not furcate at the ends. 



