70 



THE AMEKICAN MONTHLY 



[April, 



Family I. Palmellace^ Kirchner. j 



Cells single, free or united by a gel- t 



atinous envelope, connecting stems, , 



etc., into large or small, mostly slimy | 



or gelatinous, families. I 



Reproduction by vegetative cell- 

 division and formation of zoogonidia. 1 

 Copulation of zoogonidia has not been I 

 observed in this family. 



a. Single cells, separate, or not | 

 forming definite families. (Sepa- 

 ratee. 



Synopsis of Genera. 



Cells single, spherical, floating ; en- 

 velope thick. Eremosp/iera^ I. 

 Cells separate in small, indefinite 

 families ; envelope thin. 



Pleurococcus., 2. 

 Cells oblong ; floating, or attached by 

 hyaline pedicel. Dactylococcus., 3. 

 Cells oblong, single or in rows. 



Stichococcus^ 4. 

 Cells cylindric, straight or curved ; in 

 series end to end or bundles. 



Raphidiuni^ 5. 



b. Cells united in families by the 

 envelope of the mother-cell enclosing 

 the daughter-cells. (Inclus^.) 



Synopsis of Genera. 



Cells distributed in large, gelatinous, 

 spherical families. Botrydina., 6. 



Cells oval ; in botryoidal, lobed fam- 

 ilies. Botryococcus., 7* 



Cells enclosed in globose, lamellose 

 envelopes. Gla'ocystis^ 8. 



Cells red, on thick gelatinous stalks 

 of concentric lamellose structure. 

 Urococcus^ 9. 



Cells kidney-shape, lying separate in 

 ample, gelatinous envelope. 



JVepkrocytiiim, 10. 



Cells oblong, in common gelatinous 

 envelope. Oocystis, 11. 



Cells oval, with large, colorless vac- 

 uole ; in common, gelatinous en- 

 velope. Gioeococcus., 12. 



c. Cells united in families of char- 

 acteristic form by the formation of 

 slimy and confluent envelopes. (Gel- 



ATINOS^.) 



Synopsis of Genera. 



Cells oval, in tubular, branched, gela- 

 tinous thallus. HydniruSy 13. 

 Thallus globose, eight-celled, float- 

 ing. ChromopJiyton., 14. 

 Cells in hyaline, cylindrical, single or 

 radiately ari'anged envelopes. 



Pahnodactylon., 15. 

 Cells longitudinally arranged in tubu- 

 lar hyaline thallus. 



Hortnospora., 16. 

 Cells in hyaline envelopes, the latter 

 joined into a long thallus. 



Palmodictyon., 17. 

 Cells distributed in a hyaline thallus 

 attached by a pedicel-like base. 



Apiocystis., 18. 

 Cells in oval transparent envelopes in 

 a globose, hyaline thallus. 



Entophysalis., 19. 

 Cells distributed, often in twos and 

 fours, in a gelatinous layer. 



Tetraspora. 20. 

 Cells cubical, angular, in tubular fam- 

 ilies. Sta7(roge)iia., 21. 

 Cells oval, in longitudinal series in 

 gelatinous thallus. Inoderma., 22. 

 Cells in gelatinous families, integu- 

 ments splitting in halves and quar- 

 ters remaining in the gelatin. 



Sc/iizoc/ilatnys, 23. 



Cells green, red, or orange, thick 



walls ; indefinite gelatinous thallus. 



Palm el I a., 24. 



Cells spherical or angular, red or 



purple, in layer of gelatin. 



Porpli rydiicm , 25 . 



d. The single cells are united in 

 families b}' the formation of pedicels 

 or fine stems. (Stipitat^.) 



Synopsis of Genera. 



Cells elliptic, on ends and at axes of 

 dichotomous, hyaline stems. 



Cosmocl adium ^ 26. 

 Cells terminal, on stems. 



Mischococcus., 27. 

 Cells terminal, on very delicate stems, 

 in spherical hyaline thallus. 



Dictyospha;rium., 28. 

 Cells in fours, on very short branch- 

 ing stems. DimorpJiococctis., 29. 

 Cells on radiating gelatinous st^m§ 



