42 WISCONSIN PHYTOPLANKTON 



t 



APHANOCAPSA ELACHISTA var. CONFEKTA W. & G. S. West. PI. 2, Fig. 8. 

 Jour. Linn. Soc. Bot. 40: 432, pi. 19, fig. 1. 1912. 



Colonies small, spherical, ovoid, or irregular; with the cells enclosed 

 by a gelatinous, homogeneous, hyaline or ochraceous envelope. Indi- 

 vidual sheaths of cells confluent with colonial envelope. Cells spheri- 

 cal, fairly close together. Cell contents homogeneous, grey to pale 

 blue-green. (Euplanktont). 



Diana, cells 1.6-2.0 /*. Colonies up to 75 ^ broad and 100 p long. 



Birch Island (rr), Crawling Stone (rrr), Deer (ss), Lindy (r), Nancy (r), 

 Pine Tree (ss), Silver (2) (rr). 



var. planctonica var. nov. PI. 3, Fig. 3. 



Cells spherical, some distance from one another. Sheath enclosing 

 colony always hyaline. Contents of cells pale grey. (Euplanktont). 

 Diam. cells 2-3 p. 



Bear (1) (s), Bear Trap (rr), Poplar (ss), Round (3) (rr), Sand (1) (r). 



Differing from the typical form in the larger cell size and grey color 

 of the cell contents. 



Aphanocapsa endophytica sp. nov. PI. 2, Fig. 10. 



Colonies endophytic within the gelatinous sheath of Microcystis col- 

 onies and with their envelopes confluent with the envelope of the host 

 colony. Cells spherical, equidistant from one another or in small 

 clumps. Cell contents homogeneous, grey to bright blue-green. (Eu- 

 planktont). 



Diam. cells 2 /i. 



Poor Farm (ss). 



The occurrence of bacteria in the gelatinous envelope of colonial 

 Myxophyceae is a familiar phenomenon to the limnologist. The blue- 

 green color of the cells endophytic within the envelopes of Microcystis 

 colonies in Poor Farm Lake precludes their recognition as bacteria. 

 (See G. S. West's remarks concerning a similar endophytic Aphano- 

 thece in Jour. Linn. Soc. Bot. 40: 432. 1912). 



APHANOCAPSA PULCHRA (Kiitzing) Rabenhorst. PI. 2, Fig. 9. 

 Flora Eur. Algarum 2: 49. 1865. 



Colonies macroscopic or microscopic, free-floating or sessile, generally 

 spherical to ovoid when found in the plankton. Sheath of colony gela- 

 tinous, firm, hyaline, homogeneous; with the cells some distance from 



