18 



MEMOIRS OF THE XEW YOKK BOTAXICAL GARDEX 



I am excluding such species from the genus Gloeucapsa even 

 though some species may have differentiated teguments within 

 the colonial tegmnent, and thus emending the genus as under- 

 stood by Naegeli and followed by later writers. The inclusion 

 of such forms undoubtedly has led to the statement that resting 

 spores are produced by certain species of Gloeocapsa. "West's 

 Gloeocapsa gig as from the AVest Indies clearly belongs to the 

 Anacystis lineage. 



Setchell and Gardner*^ have shown that Kuetzing's Micro- 

 cystis, 1833, was not homogeneous and most of its species are 

 to be referred to a different group of organisms from the Myxo- 

 phyceae. 



Anacystis nigropurpurea sp. nov. 



Plate 3, figure 33 



Colonies subspherical, free, 25-40 m (up to 7U|j) diam. ; cells 

 spherical to slightly ellipsoidal, 8.5^.5 \i diam., with a distinct 

 dark purplish wall, contents homogeneous, obscured by the more 

 or less opaque wall, moderately close together, arranged without 

 order in the colony ; resting cells 5-6 n diam., with dark, smooth, 

 homogeneous Avail; tegument hyaline or opalescent, homogene- 

 ous, close-fitting or with a distinct clear margin between the cells 

 and the surface. 



Growing in depressions in limestone between Hatillo and 

 Arecibo, no. 1387 a, type ; on limestone, Hato Arriba, Arecibo, 

 nos. 1397 a and 1399 c ; on a waterpipe in company with other 

 Myxophyceae, Maricao, no. 1155 f; on the wall of a church, Sa- 

 bana Grande, no. 962 h ; on bark along the road to Monte Mon- 

 toro, Maricao, no. 1087. 



This species of Anacystis is one of a few species in which the 

 cells develop a distinct, colored wall very early in the life cycle. 

 The distinction between the vegetative cells and the resting 

 spores is slight. The latter are somewhat larger and the cell 

 walls are thicker, but of the same color and consistency. 



Anacystis nigropurpioea seems closely related to A. nigro- 

 violacea of this paper. The former has more and smaller cells 

 in a colony than the latter. The especially distinguishing fea- 

 ture separating the two species is in the method of development. 

 In germination, the resting spore of A. nigropurpurea appar- 

 ently retains the spore wall, which, however, becomes thinner, 



oUniv. Calif. Publ. Bot. 8: 13. 1919. 



