HOW TO KNOW THE SEAWEEDS 



37b Branchlets mostly not contracted at the base, 750 ix or more in 

 diameter. Figs. 63, 64 Laurencia (in part) 



Figure 63 



Fig. 63. Laurencia spp. (tetrasporangial branch apices) 



Two examples of upper branches of tetrasporangial plants to 

 show the slight contraction at the base of branches compared to the 

 prominent contraction in Chondria. A. X 5; B. X 9. 



Fig. 64. Laurencia spp. (habit) 



A. Laurencia papillosa (Forskal) Greville. Habit of a portion of a 

 clumping plant, X 1.5. B. Laurencia ohtusa (Hudson) Lamouroux. Habit 

 of a portion of a clumping plant, X 1.5. Both of these species are com- 

 mon along the coasts of Florida and the Gulf of Mexico. Several other 

 cyhndrical species occur more or less commonly in Florida and also 



58 



