208 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 12 



This plant appears to be close to Pachymenia cuticulosa Howe (1914, 

 p. 171, pi. 63, text-fig. 4). The chief differences seem to lie in the thicker 

 prostrate thallus with narrower branches which do not tend to have entire 

 margins, the thinner outer cortex of more slender and closer anticlinal 

 cell rows inside a softer and probably thinner cuticle, and the longer tet- 

 rasporangia which, since they were found in some sections and not in 

 others nearby, may be formed somewhat locally. 



Ecuador: Archipielago de Colon, appressed to rocks, especially in 

 crevices, intertidal ; Black Beach Anchorage, I. Santa Maria, no. 34-256 

 rryP^AlSJan. 1934. 



POLYOPES J. Agardh, 1849 



Thallus flat, dichotomously branched, the segments strap shaped and 

 sometimes contracted slightly, of firm consistency; structurally showing a 

 dense filamentous spongy medulla, the cortex also dense, of anticlinal rows 

 of cells, within somewhat looser and larger, closer and of smaller cells 

 without; tetrasporangia and cystocarps in special fertile branch tips some- 

 what segregated by a constriction; sporangia in slightly elevated nema- 

 thecia, tetrapartite ; cystocarps very small, immersed in the locally thick- 

 ened branch tips, lying in the inner cortex and somewhat extending into 

 the medulla, with a spongy filamentous pericarp. 



Polyopes Bushiae Farlow 



Plants to 8 cm tall, dark reddish purple, texture firm fleshy, habit 

 dichotomously branched, the branches above more close and fastigiate; 

 flat throughout except near the base, to 3 mm broad below and but 1.0- 

 1.5 mm in the ultimate branches; structurally showing a dense firm inner 

 medulla of very slender filaments with coalesced walls, surrounded by a 

 zone of larger filaments appearing subparenchymatous in transverse sec- 

 tion, the cortex of anticlinal cell rows 3-5 cells long, the walls firm and 

 closely joined, at least the outer 2-3 cells rectangular in section. 



Farlow 1900, p. 75. 



This material is of a more lax habit than that issued without descrip- 

 tion under the name of Cryptonemia Bushiae Farlow ms. in Phyc. Bor.- 

 Amer. no. 600 (1899), but not essentially different. The histological 

 features of the two collections agree exactly. They show a great structural 

 similarity to Prionitis. In this they differ sharply from Setchell & Gard- 

 ner's ( 1924, pi. 28, fig. 61) figure of Polyopes sinicola, where the medulla 

 of delicate filaments passes directly into the cortex, which has much longer 



