Phylum Rhodophyta [41 



1. Cells with protoplasmic interconnections, 

 containing except in the lowest examples sev- 

 eral parietal plastids, organized as filaments 

 with apical growth, the filaments usually 

 massed as thalloid bodies; zygotes giving rise 

 to spores indirectly Class 2. Heterocarpea. 



Class 1. BANGIALEA (Engler) Wettstein 



Subclass Bangioideae de Toni Sylloge Algarum 4: 4 (1897). 



Subclass Bangiales Engler in Engler and Prantl Nat. Pflanzenfam. I Teil, Abt. 2 : 



ix (1897). 

 Class Bangiales Wettstein Handb. syst. Bot. 1: 187 (1901). 

 Class Bangioideae and orders Bangiales and Rhodochaetales Bessey in Univ. Ne- 

 braska Studies 7: 291 (1907). 

 Class Bangieae SchaflFner in Ohio Naturalist 9: 448 (1909). 

 Protoflorideae Rosenvinge in Mem. Acad. Roy. Sci. Lett. Danemark, ser. 7, 



Sciences 7: 55 (1909). 

 Abtheilung (of Stamm Rhodophyta) Bangiineae Pascher in Beih. bot. Centralbl. 



48, Abt. 2: 328 (1931). 

 Subclass Protoflorideae Smith Freshw. Algae 120 (1933). 



Red algae (exceptionally green or of other colors), the cells with solitary central 

 plastids (exceptionally with multiple parietal plastids), lacking protoplasmic inter- 

 connections, in irregular colonial masses or forming filaments or thalli with intercalary 

 growth; the zygote produced in sexual reproduction dividing to produce spores 

 directly. 



The group is of one order, five families, about fifteen genera; the number of 

 known species is about eighty. 



Order Bangiacea [Bangiaceae] Nageli 1847. 

 Characters of the class. 



1. Cells forming irregular aggregates Family 1. Porphyridiacea. 



1. Cells forming filaments or thalli. 



2. Vegetative cells becoming spores with- 

 out dividing Family 2. Rhodochaetacea. 



2. Vegetative cells undergoing division to 

 produce spores. 



3. Organisms red, purplish, etc Family 3. Porphyrea. 



3. Organisms green Family 4. Schizogoniacea. 



2. Spores formed solitary in special cells Family 5. Compsopogonacea. 



Family 1. Porphyridiacea [Porphyridiaceae] Kylin in Kungl. Fysiog. Sallsk. 

 Forhandl. 7, no. 10: 4 (1937). Order Porphyridiales Kylin 1. c. The only well known 

 species is Porphyridium cruentum (C. Agardh) Nageli (1849). It is widely dis- 

 tributed in damp climates, forming extensive red patches like blood on damp earth or 

 stone. The spherical cells are reported as varying widely in diameter (5-24^), and 

 Geitler (1932) and Kylin (1937) have distinguished additional species. 



Porphyridium has been classified among blue-green, red, and green algae. Lewis 

 and Zirkle (1920) found in each cell a central red plastid, occupying most of its 

 volume, and having rays extending to the cell membrane. Within the plastid there is 



