NO. 1 TAYLOR: PACIFIC MARINE ALGAE 159 



Pterocladia musciformis n. sp.^^ 



Plants forming mosslike turfs about 1 cm tall, with decumbent fili- 

 form rhizomes 80-100 fi diam., which at intervals bear short, stout, little- 

 expanded lateral branches on the lower side and on the upper erect foliar 

 branches which are at first subcylindrical, later, above, linear oblanceolate 

 and to 5-8 mm long, 220-450 ju, broad; foliar branches irregularly to 

 marginally sparingly pinnately branched, the branches similar to the 

 primary blade; growth by an apical cell, the axes and blades structurally 

 showing rhizines in the central medullary tissue; surface cells angular, 

 4-6 fi diam., not longer than broad ; tetrasporangial sori sometimes in 

 simple blades, more often in apically palmate to subpinnately branched 

 blades with separate sori in each division ; sori showing spores produced 

 in decussate rows, those rows near the apex younger than those more basal, 

 in old sori all spores discharged and the soiois area becoming perforate; 

 sexual reproduction not observed. 



These plants considerably resemble Bornet's Gelidium melanoideum 

 (Feldmann & Hamel 1936, p. 232, figs. 15, 16), but the blades tend to 

 be more oblanceolate, the rhizines are more conspicuous and show the 

 characters of Pterocladia, and the surface cells are not longitudinally 

 elongate. It is notable that in only this species of Gelidium where the 

 cystocarps are unknown and the rhizines doubtfully distinctive are the 

 spores reported to be in decussate rows; one anticipates that it may be 

 shown to be a Pterocladia also, when the cystocarps are found. 



Costa Rica: abundant on the rocks, much admixed with sand, as- 

 sociated with Centroceras clavulatum and Gelidium pusillum, Golfo 

 Dulce, no. 39-106 (tetrasporic, TYPE), 26 Mar. 1939. 



Pterocladia mexicana n. sp.^^ 

 Plate 35 

 Plants to 1 dm tall, very bushy, dark red, firmly fleshy, several 

 branches arising from near the base, these in turn progressively 3-4 times 



94 Pterocladia musciformis n. sp. — Planta bryoidea, 1 cm altitudine, rhlzomati- 

 bus 80-100 11 diam., ramos hapterales foliaresque ferentibus, his infra subcylindricis, 

 supra lineari-oblanceolatis, 5-8 mm long., 220-450 M- irregulariter aut marginaliter 

 pinnate ramosis, rhizinas intra medullam centralem habentibus; soris ferentibus 

 tetrasporangia in ordinibus decussatis prope apicem laminarum fertilium orienti- 

 bus. Planta typica in loco dicto Golfo Dulce, Costa Rica, legit W. R. Taylor no. 

 39-106, 26 Mar. 1939. 



95 Pterocladia mexicana n. sp. — Plantae ad 1 dm altitudine, fruticosae, firme 

 carnosae, singulis ramis primariis 3-4-pinnatis, divisionibus externis complanatip, 

 paululum triangularibus; axibus primariis 1.0-1.2 mm_ lat., compressis; ramis 

 lateralibus brevibus, in basi nudis, supra pinnatis, ramulis 0.2-0.5 mm lat., paulu- 

 lum compressis; ramulis tetrasporangiatis similibus sed compressioribus quara 

 ramis ver:etativis, soris linearibus circa % latitudinem laminae occupantibus, sporis 

 in ordinibus vix decussatis positis. Planta typica in loco dicto Point Hughes, Cabo 

 San Lazaro, Baja California, Mexico, legit W. R. Taylor no. 34-601, 7 Mar, 1934. 



