270 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 3 



Two additional collections of this unique and attractive species have 

 recently been obtained. They have been compared with a specimen of the 

 type collection and found to agree well. Variation is prominent in the 

 degree of branching and in the thickness and extent of the flat segments. 



D. 591, dredged in 12-26 m., San Lorenzo Channel, Feb. (Diguet's 

 type specimens came from very near this locality) ; D. 281, dredged in 

 Mejia Channel, Puerto Refugio, 12-22 m., Jan. 



Lithophyllum veleroae sp. nov. 

 Plate 55, Fig. 5; Plate 56, Figs. 1-4 



Frondes in forma globorum sphericorum, 4-6 cm. diam., semisolidae, laminis 

 multifariam radiantibus anastomosantibusque compositae; conceptaculis tetraspor- 

 angiiferis immersis, 225-275 jx diam., 100-125 n altis, columnam centralem para- 

 physium et porum singulum apicale ostendentibus. 



Thallus forming rounded galls 4-6 cm. diam., semisolid, formed of 

 anastomosed plates radiating in all directions; outer surface intricately 

 designed by the wavy, intersecting double margins of the plates, the edges 

 of each of the major anastomosing plates parted at the surface into two 

 sharp ridges bordering a shallow channel (much as in some forms of L. 

 dentatum) ; these channels and ridges sometimes more or less continuous, 

 sometimes broken, give the plant a distinctive appearance; thallus com- 

 posed of a massive hypothallus of more or less radiating rows of oblong- 

 rectangular cells 16-20 jx high, grading into a usually well-developed peri- 

 thallus of square or subspherical cells 9-10 /* high, in compact vertical 

 rows; perithallus sometimes highly developed and stratified; tetraspor- 

 angial conceptacles immersed, 225-275 /* diam., low, 100-125 /a high, with 

 a median paraphysis column and a single apical pore; tetrasporangia about 

 45 by 22 ju, ; cystocarps and antheridia unknown. 



Type: D. 592, dredged in 12-26 meters, San Lorenzo Channel, 

 Espiritu Santo Island, Feb. 14, 1940. Herb. AHF no. 23. 



In habit this species shows considerable similarity to Lithophyllum 

 dentatum f. dilatata of the Irish coast (Foslie, 1929, pi. LXII, figs. 8, 9). 

 The channeling of the margins of the anastomosed plates is stronger, how- 

 ever, and the marginal ridges are sharper, 



Lithophyllum decipiens Foslie 



Plate 57, Fig. 20 



Foslie, 1897, p. 20; 1900, p. 71 ; Mason, p. 119, pis. 17, 18. 



Sections of tetrasporic material from the Gulf of California have been 

 compared with sections of a duplicate type and found to correspond in 

 all essential details. 



