THE PLOB \ OF M.r.i: 18K \. 



Closterinm monilifernm (Boby) Ehrb. Inf. 9L 1836. 

 Lunulina monilifera Bob* Hist. Nat d. Zooph. II. 1834. 



Crescenl shaped, inflated in the center, apex incurved, obtuse; pyrenoids 

 conspicuous, 7-10 in an axial series in each half cell; membrane hyaline, 

 without striae, vacuole Large, containing numerous corpuscles; diameter 

 of cells 30-60 /i, length 5-9 times the diameter. PL v.. Fig. 2. 



5. PENIUM Breb. in Kuetz. Sp. Alg. 1G7. 1840. 



Cells fusiform or cylindrical, straight, boldi ends rounded or truncate, often 

 slightly constricted in the middle; pyrenOids 2 many; propagation by 



cell division; zygospore globose or angular, smooth. 

 Etymology: unknown. 



Peninm closterioides Balfs Brit. Desm. 152. 1848. 



Cell narrowly lanceolate, fusiform, doubly conical, ■!<> 1 1 broad, 5 6 times as 

 long, apex truncate, empty, smooth; endochrom • in distinct Longitudinal 

 bands interrupted by a colorless median space; pyrenoids in a single 

 central series; zygospores globose, 46-GO // in diam., smooth. 

 Lincoln. PL V., Fig 6. 



«». DOCIDIUM Breb. in Kuetz. Sp. Alg. 18. 1849. 



Chloroplast axillary of 2-4 radiately disposed bands; cells straight, oblong 

 cylindrical, constricted, more or less swollen each side of the constriction 

 apex truncate; cell-membrane smooth or longitudinally plicate; vacuole 



hyaline, terminal, containing a few oscillating corpuscles; zygospore 

 globose. 

 Etymology: Greek, Soiug, stick. 



Docidinm bacul ina Breb. in Ralfs Brit. Desm. 158. 1848. 



Cylindrical, 14-22 /i broad, 10 20 times as long, l>ut slightly attenuate to t In- 



apex, which is truncate or rounded; membrane hyaline, smooth. 

 Thedford. PL V., Fig. 4. 



7. PL.EUROTAEKIU9I Naeg. Einzell. Alg. 104. 1849. 



Cells straight, cylindrical, longitudinally striate, apex truncate, more or l< 88 

 inflated each side of a median constriction; ohloroplasta parietal, never 

 axillary; vacuoles apical, containing oscillating corpuscles. 



Etymology; Greek, Tv?.tvpa, side, and ratvta, fillet. 



Plenrotaeiiinin nodulosum (Bbeb.) DeBab? Conjug. 7.".. 1858. 



Robust, subclavate cylindrical, LO 66 broad, 1" 20 times as Long, undulate 



nodose near the center, inflated on each side of the median constriction. 



apex broadly truncate; membrane granulate-punctate. 

 Minden. PL V., Fig. 5. 



8. XAKTHIDIIT91 Ehrb. Abh. Berl. Akad. 317. 1833. 



Single or concatenate, deeply constricted: segments broader than long, com 

 pressed, entire, spiny; spine-, simple or bifurcate, in two to eight series, 

 protruding in the center as a roundel or truncate t uberole; ohloroplasts 

 parietal, lamelliform; zygospore smooth or spiny. 



Etymology: Greek, §avdog, yellow. 



