THE GREEN ALGAE OF NORTH AMERICA 411 



Stolon naked; fronds simple or branched, terete or annulate, bear- 

 ing distichous or tnultiseriate, ovoid, clavate, cylindrical or 

 linear, sessile or pedicellate ramuli. 12. SEUOIDEAE. 



KEY TO THE SPECIES OK CAULERPA. 



i. Stolon wanting. 16. C. ambigua. 



I. Stolon present. 2. 



2. Stolons and fronds filiform, without distinct ramuli. 



i. C. fastigiata. 



2. Stolons and fronds different in character. 3. 



3. Fronds very slender, ramuli whorled, near the summit. 4. 



3. Fronds stouter, ramuli not in distinct, distant whorls. 5. 



4. Not over i cm. high ; stolon and base of fronds hairy. 



2. C. pus ilia. 



4. Up to 5 cm. high ; hairs wanting or few. 3. C. verticillata, 



5. Stolons naked. 6. 



5. Stolons with hairs or ramuli. 13. 



6. Fronds flat. 7. 



6. Fronds terete or compressed. n. 



7. Margin entire. 5. C. prolifcra. 



7. Frond pinnate, with linear-lanceolate outline. 8. 



7. Frond narrowly linear, more or less twisted, with frequent con- 

 strictions, ii. C. Freycinetii. 



8. Pinnules flat. 6. C. crassifolia. 



8. Pinnules cylindrical or compressed. 9. 



9. Pinnules terete, tip obtuse, somewhat clavate. 8. C. Ashmeadi. 

 9. Pinnules mucronate or tapering at tip. 10. 



10. Pinnules narrowed at base and tapering to tip. 7. C. taxifolia. 



10. Pinnules at base somewhat larger than the curved and mucronate 

 tip. 9. C. sertular aides. 



ii. Frond with naked primary axis and ramelliferous secondary axes. 



13. C. paspaloides. 

 ii. Frond without distinction in character between axes of different 



orders. I2 - 



12. Frond beset with ramuli varying from long-clavate to spherical- 

 pedicellate. 14- C. racemosa. 

 12. Frond with peltate ramuli. 15- C. peltata. 

 12. Frond more or less angled, with short ramuli of varying forms, 



the lowest always " rostriform." 12. C. cupressoides. 



13. Fronds beset with more or less densely branching ramuli. 



4. C. Webbiana. 

 13. Fronds beset with very densely set simple or bifid ramuli. 



10. C. Lycopodinni. 



i. C. FASTIGIATA Montague, 18383, p. 19, PI. II, fig. 3; 

 Weber, 1898, p. 262, PI. XX, figs, i and 2 ; Vickers, 1908, p. 



