NO. 1 DAWSON: MARINE RED ALGAE OF PACIFIC MEXICO 25 



4. Cells mostly 3-4 (5) diameters long above 



C. squarrulosum Harvey 



4. Cells mostly 1-2 diameters long above 5 



5. Cortication confined to lower parts; ultimate branches short, 



of 1-3 (4) cells C. breviramosum Gardner 



5. Cortication extensive; ultimate branches longer, of more than 



five cells 6 



6. Ultimate branches recurved and widely spreading 



C. laxum Gardner 



6. Ultimate branches incurved 7 



7. Terminal cell of branchlets 2-4 toothed .... C. pikeanum Harvey 



7. Terminal cell of branchlets acute or blunt, not toothed 



C. arborescens Gardner 



8. Asexual sporangia once divided into bispores 



C. bisporum Gardner 



8. Asexual sporangia twice divided into tetrasporangia 9 



9. Tips of ultimate branchelts pointed or aculeate (Note: some- 

 times acute in C. soccoriense) 10 



9. Tips of ultimate branchlets blunt, or at least not pointed or 



aculeate 13 



10. Ultimate branchlets attenuated to acute tips (The type of 

 C. californicum Gardner (1927) seems to be identical 



with this) C. acutum Kylin 



10. Ultimate branchlets sharply reduced at the tip to a conical 



or aculeate terminal cell 11 



11. Branching alternate throughout 12 



11. Upper branchlets in secund, adaxial series of 2-4 from the base 

 of bearing branch C. catalinae sp. nov. 



12. Plants 1-2 cm. tall; main axes to 150 ll in diameter; 



tetrasporangia subspherical, 50-60 ll in diameter 



C. ecuadoreanum Taylor 



12. Plants 2-7 cm. tall; main axes 110-150 ll in diameter; 



tetrasporangia about 48 ll in diameter, 55 ll long 



C. soccoriense Taylor (in part) 



13. Branching dominantly distichous in middle and upper parts 



or tending to be distichous rather than multifarious 13 



13. Branching dominantly multifarious (spiral or radial) through- 

 out 20 



14. Gland cells prominent C. callophyllidicola Yamada 



14. Gland cells absent or unreported ("sparse" in C. ramosi- 



ssimum) 15 



