168 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 12 



2. Light chalky pink when dry ; about 150 fi thick ; hypothallus cells 



in tangential section low ; sporangia over 85 /i, long . P. clarionensis 



2. Brownish or yellowish when drj^- to 450 /a thick; hypothallus 



cells in tangential section tall ; sporangia under 85 /i, long P. calcea 



Peyssonnelia rubra (Greville) J. Agar dh, ^roA:. 



Mexico: Is. Revilla Gigedo, frequent as dredged from 37 meters' 

 depth at sta. 132, Braithwaite Bay, I. Soccoro, no. 34-40B, 2 Jan. 1934. 

 Ibid., dredged from 58 meters' depth off Sulphur Bay, I. Clarion, at sta. 

 136, no. 34-62, 5 Jan. 1934. Ibid., dredged from 92 meters' depth at 

 sta. 137, no. 34-75, 5 Jan. 1934. Ibid., dredged from 50-75 meters' 

 depth at sta. 917, no. 39-27, 16 Mar. 1939. Ibid., dredged from 46 

 meters' depth at sta. 919, no. 39-35, 17 Mar. 1939. 



Peyssonnelia clarionensis n. sp.^''** 



Plants closely crustose, except at the margin, to 2 cm diam. or more, 

 chalky pink when dry, firmly calcified below and brittle; rhizoids numer- 

 ous; basal layer single, consisting of cells in occasionally branched radial 

 rows, 30 fi long radially, 20 ^i wide, and about 22 {x tall, supporting verti- 

 cal filaments which are once or twice forked below, 9-16 fi diam,, the cells 

 of the middle portion about one half longer than broad and rectangular 

 in sectional view, the end cells rounded-hemispherical, 6 fx diam., 4.5 /a 

 tall, the total thickness being about 150 jn; sporangial sori scattered, small, 

 0.5-0.8 mm diam., the tetrapartite sporangia oval, to 85-133 fx long, 45- 

 60 fx broad, associated with laterally free clavate paraphyses about 125- 

 150/1, long, 10 /i diam. at the top, with elongated cells below, short ones 

 near the end. 



Mexico: Is. Revilla Gigedo, on fragments of coralline algae dredged 

 at 56 meters' depth at sta. 134 off I. Clarion, no. 34-74C, 5 Jan. 1934. 

 Ibid., sta. 137 at 103 meters' depth, no. 34-68, 5 Jan. 1934. Probably 

 also: Ecuador: Archipielago de Colon, intertidal growing on barnacles, 

 Tagus Cove, I. Isabela, no. 34-146, 13 Jan. 1934. 



100 Peyssonnelia clarionensis n. sp. — Plantae crustosae, ad 2 cm diam., bene 

 calcifactae atque fragiles, multa rhizoidea habentes ; hypothallo constante ex unico 

 strato cellularum, in ordinibus radialibus dispositarum, 30 \x long., 20 \x lat., 22 

 H alt. ; perithallo 150 \i crass., constante e filamentis verticalibus, infra 9-16 \x diam., 

 his cellulis 1.5 diam. long., supra circa 6 \x diam., 0.6 plo diam. long.; soris spo- 

 rangialibus dispersis, 0.5-0.8 mm diam., sporangiis 85-133 f,i long., 45-60 |li diam.; 

 paraphyses clavatas 125-150 M- long., 10 \i diam. habentibus. Planta typica in loco 

 dicto I. Clarion, Mexico, legit W. R. Taylor no. 34-74C, 5 Jan. 1934. 



