414 
PACIFIC SCIENCE, Vol. XV, July 1961 
Lithothamnium giganteum L. Mason 
Dawson, I960; Dawson, Neushul & Wild- 
man, I960 
Southern Calif, to central Baja Calif.; Bahia 
Petatlan, Guerrero; Corinto, Nicaragua ? 
Lithothamnium guadalupensis Dawson 
Dawson, I960 
Isla Guadalupe, Baja Calif. 
Lithothamnium heteromorphum (Foslie) Foslie 
Dawson, 1957£ 
Golfo de Nicoya, Costa Rica ? 
? Lithothamnium laeve (Stromfelt) Foslie 
Dawson, I960 
Vicinity of Isla Cedros, Baja Calif. 
Lithothamnium lamellatum Setchell & Foslie 
Smith, 1944; Doty, 1947; Dawson, I960; 
Dawson, Neushul & Wildman, I960 
Oreg. to central Baja Calif. 
Lithothamnium lenormandii (Areschoug) Foslie 
Dawson, I960 
Throughout Pacific Baja Calif.; northern Gulf 
of Calif.; Bahia Santiago, Colima; Puerto 
Guatulco, Oaxaca 
Lithothamnium montereyicum Foslie 
Smith, 1944; Dawson, 1949; Mason, 1953; 
Dawson, I960 (as possibly a form of L. 
australe ) 
Monterey; Anacapa I., Calif. 
Lithothamnium muricatum (Foslie) G. De Toni 
Scagel, 1957 
Port Renfrew, British Columbia 
Lithothamnium pad f cum (Foslie) Foslie 
Scagel, 1957; Dawson, I960; Taylor, 1945 
Vancouver I., British Columbia, to La Jolla, 
Calif.; Isla Grande, Guerrero ?; Galapagos 
Arch. ? 
Lithothamnium phy mat odeum Foslie 
Scagel, 1957 
Whidbey I., Wash., to Pacific Grove, Calif. 
Lithothamnium pocillum Lemoine 
Taylor, 1945 
Galapagos Arch. 
Lithothamnium volcanum Dawson 
Dawson, I960 
Santa Cruz I., Calif.; Cortez Bank; Isla Mag- 
dalena, Baja Calif. 
Polyporolithon conchatum (Setchell & Foslie) 
L. Mason 
Scagel, 1957 
Southern British Columbia to Cambria, Calif. 
Polyporolithon par cum (Setchell & Foslie) L. 
Mason 
Scagel, 1957 
San Juan I., Wash., to Carmel, Calif. 
Polyporolithon re clinatum (Foslie) L. Mason 
Scagel, 1957 
Vancouver I., British Columbia, to La Jolla, 
Calif. 
Clathromorphum compactum (Kjellman) Foslie 
Mason, 1953 
St. Michael, Norton Sound, Alaska 
Clathromorphum circumscriptum ( Stromfelt ) 
Foslie 
Mason, 1953 
Aleutian I. to Unalaska, Alaska 
Hydrolithon arenicolum Dawson 
Dawson, I960 
Scammon Lagoon, Baja Calif. 
Hydrolithon conicum Dawson 
Dawson, I960 
Isla Socorro, Revillagigedo Arch. 
Hydrolithon reinholdii (Weber van Bosse & 
Foslie) Foslie 
Dawson, I960 
Revillagigedo Arch. 
Hydrolithon setchellii (Foslie) Setchell & L. 
Mason 
Dawson, I960 
Redondo to La Jolla, Calif.; Isla Guadalupe, 
Baja, Calif. 
