8QUAMAEIACEAE. 585 



Thallus plane or becoming verrucose or mammlllate, the 

 surface minutely and Irregularly tessellated ; concep- 

 tacles 300-iOOu in diameter. 3. a. BoergesenU. 



Thallus with rounded-obtuse or subtruneate warts or 

 bosses 4-10 mm. broad and high ; superficial layers 

 exfoliating along concentric or zonate lines ; conceptacles 



1-1.2 mm. in diameter. 4. a, dispalatum. 



Thallus frutlculose, the primary crust usually disappearing or 

 concealed by the erect branches. 

 Branches much anastomosed, compressed or subterete and 

 1.25-3.1 mm. in diameter, or becoming flabellate or some- 

 what foliar and 10-25 mm. broad by 1-2 mm. thick. 5. G. acropetum. 

 Branches terete or subterete. 



Plants attached, the intertangled frequently anastomosing 



branches forming rather compact cushions. 6. G. decutescens. 



Plants commonly free, the branches mostly erect and strict 

 or, in free-lying conditions, few, elongate, and very ir- 

 regular or somewhat cervicorn. 7. O. strictum. 



1. Goniolithon solulDile Fosl. & Howe, K. Norske Vidensk. Selsk. Skr. 1907°: 



21. 1907. 



Goniolithon Notarisii propinquiim Fosl. loo. cit. 1899=: 21. 1900. 

 Goniolithon propinquum Fosl. loc. cit. 1908'': 4. 1908. 

 Lithophyllwm (?) propinquum Lemoine, in Borg. Dansk Bot. Ark. 3': 166. 

 /. 161, IGS. 1917. 



The name solubile appears to be the first name given to this plant in the 

 specific category, propinquum antedating it as a form name only. 



On old corals, coral pebbles, and old shells in shallow water, sometimes cover- 

 ing and smothering living corals of fruticose habit. Rose Island, Great Bahama, Cat 

 Island, Atwood Cay, llariguana, and Castle Island : — 'Florida to Barbados. Type 

 from Culebra Island, Porto Rico. 



2. Goniolithon accretum Fosl. & Howe, Bull. N. Y. Bot. Gard. 4: 131. pi. 85. f. 



S; pi. 91. 1906. 



Lithophyllum accretum Lemoine, in Borg. Dansk Bot. Ark. 3': 159. 1917. 



On surf-beaten limestone rocks near low-water mark or in tide-pools or on old 

 corals or pebbles. Berry Islands, South Cat Cay, Watling's Island, Mariguana. and 

 Castle Island : — ^Florida to American Virgin Islands. Type from Sand's Key, E^orida. 



3. Goniolithon Boergesenli Po^l. K. Norske Vidensk. Selsk. Skr. 1900° : 19. 1901. 



Porolithon BoergesenU Lemoine, in Borg. Dansk Bot. Ark. 3': 178. /. 

 168, 169. 1917. 



On old shells, corals, and calcareous pebbles in shallow water. Berry Islands, 

 Mariguana, and Caicos Islands : — Florida to Barbados. Type from St. Croix. 



4. Goniolithon dispalatum Fosl. & Howe, K. Norske Vidensk. Selsk. Skr. 



1908'^: 6. 1908. 

 On calcareous rocks at low-water mark, Atwood Cay. Type from Atwood Cay. 



5. Goniolithon acropetum Fosl. & Howe, Bull. Torrey Club 33 : 577. 1906. 



Lithophyllum acropetum Lemoine, in Borg. Dansk Bot. Ark. 3': 151. 1917. 



Sometimes approaching G. decvtescens and G. striatum, which appear to inter- 



frade and forms of which are close to the earlier-published G. frutescens of the 

 outh Pacific. 



On old corals and calcareous rock in shallow water. Cat Island and Salt Cay : — 

 Porto Rico, Type from Culebra Island, Porto Rico. 



6. Goniolithon decutescens (Heyd.) Fosl.; M. A. Howe, in Britton, Fl. Ber- 



muda 538. 1918. 

 Lithothamnium {?) decutescens Heyd. Bot. Jahrb. 28: 541. pi. 11. f. 7. 



11 Ja 1901. 

 Goniolithon (?) spectaUle Fosl. K. Norske Vidensk. Selsk. Skr. 1900V 16. 



F1901. 

 38 



