472 Wisconsin Academy of Sciences, Arts, and Letters. 
are quite like S. longus var. brevispina in size and arrange¬ 
ment. 
Var. ellipticus (West and West) nov. comb. (PL 
XXVII: Fig. 44.) 
S. quadricauda var. ellipticum. West and West, 1895, p. 83; 
PL V, Fig. 6. Balsamo, 1900, p. 266. G. S. West, 1904, p. 287 
Collins, 1909, p. 169. 
S. ellipticus. Chodat, 1913, p. 69. 
“Var. cellulis perfecte ellipticis, 4 in seriem rectam dispo- 
sitis, cellulis terminalibus spinis binis validis curvatis ex- 
trorsum, cellulis medianis spina singula curvata extrorsum 
alternatim dispositis ornatis. Long. cell. 14-15 y; lat. cell. 
7.5 p.” 
Known only from Madagascar (West and West) and Bar¬ 
bados (G. S. West). 
Var. dispar (de Breb) nov. comb. (Pl. XXVII: Fig. 41.) 
Scenodesmus dispar, de Brebisson, 1856, p. 159; PI. I, Fig. 32, 
Archer, 1861, p. 753. 
S. dispar. Rabenhorst, 1868, p. 65. Lagerheim, 1883, p. 65, 
de Toni, 1889B, p. 566. Balsamo, 1900, p. 266. West and West, 
1902B 5 p. 64; PL I, Fig. 10. Adams, 1908, p. 35. 
S. quadricauda var. dispar Brunnthaler, 1913, pp. 168, 171. 
“S. corpusculis fusiformibus, oblongis, binis vel quater- 
nis irregulariter alternantibus, duobus primis uno apice cus- 
pidatis altero muticis, duobus aliis similibus sed reversis, 
extrimis dorsi apice cuspidatis.” 
The position of the spine is probably valueless in differ¬ 
entiating this from the other varieties. The pointed ends 
of the cells distinguish this variety from the others. It has 
been found in England (West and West) and France (de 
Brebisson). 
var. apiculatus (West and West) nov. comb. (Pl. 
XXVI: Fig. 36.) 
S. alternans var. apiculatus. West and West, 1894, p. 16; PL 
II, Fig. 38. West and West, 1897B, p. 500. West and West, 
1902B, p. 63. 
S. bijugatus var. alternans forma apiculatus. Chodat, 1902, p. 
213. Brunnthaler, 1913, pp. 169, 172. 
