CHROOCOOCACEAE. 619 



In 3 dm. water in a salt laKe, Watling's Island, November 25, 1907, 11. A. Howe 

 5091 (type), 5092, 5100. 



The general gelatine is very thin, hardly perceptible except by use of stains ; 

 at first glance the plant would be taken for a species of Synechocystis. Some of the 

 cells, usually those near the surface of the colony, show a thicker tegument outside 

 the very thin cell wall. Its nearest relative appears to be A. Zanardinii (Hauck) 

 llausg.* of Southern Europe and Borneo, which has cells of much the same dimen- 



* The record in Forti, Syll. Myx. 68. of the occurrence of A. Zanardinii in North 

 America "Massachusetts (Collins) " is wrong. The writer has never found it, and 

 has never seen American material. 



sions, but of deeper color " viridi-smaragdino," and arranged by 2 or 4 in a firmer, 

 more sharply defined common gelatine. 



3. GLOEOCAPSA Kiitz, Phyc. Gen. 173. 1843. 



Marine ; teguments brownish. 1. O. bahamcnsis. 

 Terrestrial. 



Teguments red; cells 4.5-7 u in diameter. 2. G. Magma. 



Teguments violet or steel-blue; cells 2.5-3.5 in diameter. 3. G. liynicola. 



1. Gloeocapsa bahamensis Collins, sp. nov. 



Marina. Cellulis indivisis 4-8 /x tliam., sine membrana 3-5 fi, pallide 

 aerugineis, in familias 4-24 eellularum unitis ; tegumentis araplis, distinetis, 

 lamellosis, sub- vel perfuscis; familiis sparsis vel inter myxophyceas varias in 

 crustam fuscam compactis. 



Undivided cells 48 fi in diameter, without wall 3-5 /x in diameter, pale 

 aeruginous; teguments wide, lamellose, distinct, lighter or darker brown; fam- 

 ilies scattered or loosely compacted with other Myxophyeeae into a brownish 

 crust. 



On the border of a salt pond, east end of Mariguana, December 12, 1907, II. A. 

 Howe 5538 (type). 



The cells in this material are dividing so rapidly that single free cells are seldom 

 seen ; the wide teguments may persist through many generations of cell division. 

 G. crepidinum Thuret, the best known and most generally distributed species, has thin 

 and rather inconspicuous teguments, the cells, not including the walls, larger, the 

 color brownish. O. deusta (Menegh.) Kiitz. also has larger cells and thinner tegu- 

 ments, with cells and teguments dark green to blackish. 



2. Gloeocapsa Magma (Breb.) Kiitz. Tab. Phyc. 1: 17. pi. 22. f. 1. 1847. 



Protococcus Magma, Breb. Alg. de Falaise, 40. pi. 4. 1836. 



Among other blue-green algae, New Providence : of wide distribution inland in 

 warm and temperate regions. Type from France. 



3. Gloeocapsa lignicola Rab. Fl. Eur. Alg. 2: 41. 1865. 



On bark, New Providence, first American record : Europe. Type from France. 



4. ENTOPHYSALIS Kiitz. Phyc. Gen. 177. 1843. 

 1. Entophysalis violacea Collins, sp. nov. 



Marina. Cellulis sphaerieis, 4-5 /x diam., sine membrana 2-3 /x diam., 

 elongatis ante divisionem, atroviolaceis, membrana hyalina, incolori vel plus- 

 minus coerulescente ; cellulis 2, interdum 4, in membrana matricali persistente, 

 series longitudinales indefinitas formantibus; seriebus dense compactis in stra- 

 tum tenue firmum nigrum. 



Cells with wall spherical, 4-5 a* in diameter, becoming elongate when 

 dividing, without wall 2-3 tt in diameter, color dark violet, wall translucent, 

 colorless or more or less bluish; cells usually 2, occasionally 4 in the mother- 

 cell wall, in indefinite longitudinal series, closely packed to form a thin smooth 

 black crust. 



On rocks at low water mark, Atwood Cay, December 3, 1907, M. A. flotoe 5888 

 (type). 



E. granulosa Kiitz., the type of the genus, forms a thicker, warty and granular 



