34 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 17 



5. Thallus to 7.5 cm. high, branched at 4-6 mm. intervals; 

 medullary filaments 3.5-4.5 /a in diameter . . N. virens 

 6. Plants monoecious, regularly dichotomously branched 



Liagora ceranoides 



6. Plants dioecious, irregularly dichotomous to alternate or 



pinnate 7 



7. Plants soft, highly lubricous 8 



7. Plants rather firm, at least not highly lubricous . . . . 10 

 8. Carpogonial branches 1-2-celled before fertilization; cysto- 

 carp with a prominent involucre of long, slender filaments 



surrounding the gonimoblast cluster 



L. magniinvolucra 



8. Carpogonial branches of 3 or more cells before fertiliza- 

 tion; gonimoblast separate from involucre which remains 



beneath it 9 



9. Carpogonial branches 3-celled before fertilization, soon be- 

 coming concealed by development of gonimoblast and involucral 



filaments L. orientalis 



9. Carpogonial branches 5-6-celIed before fertilization ; gonimo- 

 blast remaining raised above the cluster of involucral filaments 

 and the enlarged lower carpogonial branch cells visible in fairly 



late stages L. abbottae 



10. Plants heavily calcified extraperipherally below tips; an- 

 theridia semi-capitate; branching dichotomous, without 

 proliferous lateral branchlets . . . L. califomica 

 10. Plants lightly calcified, mainly axially; antheridia capitate; 

 branching variable, subdichotomous to monopodial and 

 pinnate L. farinosa 



Nemalion helminthoides (Velley) Batters 



Batters, 1902, p. 59 (as N. elminthoides) ; Dawson, 1949, p. 227. 

 Nemalion lubrkum Duby, as employed by Smith, 1944, p. 186, pi. 41, 

 fig. 5. Fucus ehninthoides Velley, in Withering, 1792, p. 255, pi. 17, 

 fig. 2. Ulva elminthoides (Velley) Withering, 1796, p. 325, pi. 17. fig. 

 2. 



Thalli saxicolous, 10-40 cm. high, consisting of a small pulvinate 

 base giving rise to one or several soft lubricous, unbranched, cylindrical 

 axes ; axes somewhat undulate and gradually tapering to the apex, vary- 

 ing from 1-6 mm. in diameter in plants from different localities, but the 



