THE GREEN ALGAE OF NORTH AMERICA 



335 



40. Ramuli acute ; maiu filaments not over 60 n i 



40. Ramuli not acute. 

 41. Main branches virgate. 

 41. Branching chiefly dichotomous. 

 42. Cells of ramuli 1-2 diam. long. 

 42. Cells of ramuli 4 diam. long or more. 

 43. Main filaments about 50 /u diam. 

 43. Main filaments So n diam. or more. 6. 



44. Ramuli 20-30 /u. diam. 

 44. Ramuli 32-36 n diam. 

 45. Branching continuously dichotomous, except as to ultimate ramuli. 



9. C. Stiinpsoni. 

 45. Main branching dichotomous; lesser branches and ramuli dense, 



largely secund. 19. C. crystallina. 



Ultimate ramuli short, stout. 27. C. laetevirens. 



lium. 



2. C. glancescens. 



41. 



42. 



45. 



43. 



44. 



4. C. dclicatula. 

 C. brachyclados. 



8. C. nitida. 



5. C.virgatula. 



46. 



46. intimate ramuli long, slender. 



20. C. dalmatica, 



KEY TO THE FRESH WATER SPECIES OF CLADOPHORA. 

 i. Fronds floating, except in the early stages. 2. 



I. Fronds permanently attached. 7. 



2. Forming hard, globular masses. 52. C. holsatica. 



2. Of no definite form. 3. 



3. Main filaments stout, with short cells, bearing long, slender, secund 



ramuli. 50. C. secunda. 



3. No sharp distinction between branches of different orders. 4. 



4. Main filaments bent, cells ovoid or pyriform, branching patent. 



47. C.fracta. 



4. Main filaments straight or nearly so. 5. 



5. Main filaments long, with few branches. 51. C. insignis. 



5. Main filaments freely branching, branches with many ramuli. 6. 



6. Ramuli mostly unicellular. 



6. Ramuli pluricellular, long-celled. 

 7. Ramuli in dense terminal clusters. 

 7. Ramuli not in dense terminal clusters. 



8. Ramuli recurved. 



8. Ramuli straight or slightly incurved. 



48. C. oligoclona. 

 49. C. crispata. 



43 



10. 



declinata. 

 9. 



9. Lower branching mostly dichotomous ; branches connate for some 



44- C, canalicularis. 



distance. 



9. Branching mostly alternate ; branches not connate. 



42. 



10. Not over i cm. high ; fil. about 40 /x diam. 53. 

 10. Larger, 10-40 cm. high ; fil. 45 M diam. or more. 

 ii. Main filaments 75-125 M diam.; ramuli 35-50 M. 45* 

 ii. Main filaments 45-85 v diam ; ramuli 25-35^. 



46. C. Kuetzingiana. 



C. glomerata. 



C. uberrima. 



n. 



C. callicoma. 



