112 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 17 



Thalli forming expanded, purplish-brown or reddish, lightly calcified 

 crusts 2-5 cm. wide on rocks or shells, firmly adherent, drying without 

 splitting, the margins wavy and more or less lobed and growing irregu- 

 larly by small fan-shaped areas, in part becoming superimposed, the 

 surface provided with minute, radiating, anastomosing, discontinuous 

 ridges which show sufficient relief to be visible macroscopically, mostly 

 100-200 (or to 300) fx thick; hypothallus (as seen from below) of very 

 conspicuous converging, diverging and anastomosing fan-shaped groups 

 of cell-rows, the cells 26-30 /a long, 12-15 /x wide and 25-35 ju, high, 

 giving rise to ascending or nearly vertical, once- or twice-branched, com- 

 pact cell-rows making up the perithallus, the upper cells of these fila- 

 ments more or less quadrate, 9-10 ju, wide and somewhat shorter than 

 broad; tetrasporangial nemathecia 750 {x. wide or more, superficial, ele- 

 vated, about 90-100 ix thick, the paraphyses very slender-clavate, mostly 

 unbranched and of 5-6 cells ; tetrasporangia 60-80 fi long, 20-25 [i wide ; 

 antheridia borne in nemathecial sori about 36 ^ thick, formed by several 

 transverse and one longitudinal division of the nemathecial filaments so 

 that 10-12 antheridia occur in the length, and 2 in the width, of the fila- 

 ment, 2.5-3.2 fx in diameter; carposporic nemathecia small, 200-500 ju. 

 wide, superficial, gelatinous, bearing numerous rows of 3 or more car- 

 pospores of irregular shape, 17-28 /x. in greatest diameter. 



Type: Holotype not designated but represented by the original 

 Crouan material in the Herbarium of the Museum of Paris. Isotype 

 fragments are on sheet 54107, including slides 1573-1574, in HAHF. 



Type locality: Atlantic coast of France near Brivatem. 



Mexican distribution: Pacific Baja Calif. — D. 294, 8 km. 

 south of Punta Descanso, Jan.; Howell, 915a, Isla San Martin, Aug.; 

 D. 8609, 8218a, Isla Guadalupe, Dec; D. 2895, just south of Punta 

 Santa Rosalia, Oct.; D. 2951, Millers Landing, Oct.; D. 9869, Isla 

 Cedros, Apr.; D. 9969, 10 miles west of Punta Malarrimo, Apr. Gulf 

 of Calif. — D. 6856a, Mar., Howell 42, Aug., Bahia de San Lucas; D. 

 444a, Bahia Bocochibampo, Feb. Revillagigedo Archip. — Taylor 39-28a, 

 dredged from 50-75 m.. Mar., Taylor 39-8, shore. Mar., Taylor 34-68, 

 dredged from 102 m., Jan., Bahia Sulphur, Isla Clarion; Taylor 34- 

 40a, dredged from 37 m., Bahia Braithwaite, Isla Socorro, Jan. Nayarit- 

 D. 3710, Mira Mar, Dec. (Taylor's 34-598a from Isla Isabel seems to 

 have been mistakenly identified as this species. The material is sparse and 

 sterile but does not seem to show the characteristic hypothallus structure 

 or surface ridges of Cruoriella dubyi. ) 



