NO. 1 TAYLOR: PACIFIC MARINE ALGAE 229 



to the other, and nearly without pectinate subterminal branching, but all 

 fertile specimens have the character of P. pacificum. Consequently the 

 whole series is considered as belonging to this one species. 



Mexico: Baja California, at South Bay, I. Cerros, no. 34-626, 10 

 Mar. 1934. Ibid., Pta. San Bartolome, at Ba. Thurloe, no. 34-616, 9 

 Mar. 1934. Ibid., Cabo San Lazaro, at Point Hughes, near low tide 

 on rocks, no. 34-591, 7 Mar. 1934. Is. Revilla Gigedo, rare as dredged 

 at sta. 136 from 59 meters off Sulphur Bay, I. Clarion, no. 34-59, 5 Jan. 

 1934. Ecuador: Archipielago de Colon, rare fragments dredged at 

 sta. 143 off I. Wenman, no. 34-80, 1 1 Jan. 1934. Ibid., from the reef to 

 the north of Tagus Cove, near low tide line, I. Isabela, no. 34-161, 15 

 Jan. 1934. Ibid., floating offshore, and on surf-beaten rocks at Pt. 

 Christopher, nos. 34-196, 34-202B, 16 Jan. 1934. Ibid., I. Santa Maria, 

 Hassler Exped. no. 1014, June 1872. Ibid., occasional near low tide line 

 on rocks, Black Beach Anchorage, no. 34-220, 17 Jan. 1934. Ibid., 

 dredged off Academy Bay, I. Santa Cruz, no. 34-325, 20 Jan. 1934. 



Gracilariaceae 



Plants bushy, branched, the branches cylindrical or flattened, dicho- 

 tomously to subpalmately or pinnately divided, firm to cartilaginous; 

 structure parenchymatous; sporangia scattered on the surface, or some- 

 what aggregated, tetrapartite ; spermatangia formed in crypts ; carpogenic 

 branches of two cells, the carpogonium fusing with the cell below and 

 with others to form a large cell from which the gonimoblasts are pro- 

 duced ; cystocarp with a large basal placenta, discharging through a pore 

 in the thick, projecting pericarp. 



KEY TO GENERA 



1. Sporangia scattered; pericarp not generally connected with the 

 center of the cystocarp Gracilana 



1. Sporangia in scattered, slightly elevated nemathecia; pericarp 

 connected by sterile strands with the sterile center of the cysto- 

 carp Tylotus 



GRAGILARIA Greville, 1830 

 Plants bushy, cylindrical or flattened, fleshy to cartilaginous, dicho- 

 tomously to alternately branched, often proliferous ; structurally with a 

 broad medulla of large colorless cells and a narrow small-celled cortex ; 

 sporangia scattered at the surface of the cortex, tetrapartite ; spermatangia 

 generally formed in crypts; cystocarps spherical with a basal placental 

 tissue, the pericarp much swollen, ostiolate. 



