202 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 12 



3. Thallus flat, entire or lobed, thick and firm; cortex thick, of 

 longer antich'nal rows, medullary filaments slender, in a thick 

 dense layer Pachymenia 



4. Thallus dichotomous or pinnate, flat or compressed; medulla of 

 thin filaments, cortex loose within, dense without . . . Prionitis 



4. Thallus dichotomous ; medulla dense, netlike, cortex firm, dense 

 Polyopes 



Incertae Sedis 



5. Plants pulvinate, parasitic on Prionitis Lobocolax 



GRYPTONEMIA J. Agardh, 1842 



Gryptonemia decolorata n. sp.^^^ 

 Plate 83, Fig. 1 



Plants small, when dried dark dull reddish, to about 5 cm high, stain- 

 ing the paper dark brown, thin, firmly membranous ; irregularly branched, 

 the branches contracted at the base, the apices rounded, the margins 

 crisped and erose, submicroscopically aculeate dentate, width of branches 

 3-12 mm, thickness 80-100 /a; structurally the medulla of slender closely 

 placed intertwined filaments about 2-3 ju, diam. with coalescent walls, the 

 subcortex irregular, of about two layers, the cells depressed, the inner 

 being larger and about 9-12 fx in greater diam. ; the cortex of close-placed 

 cells, single or two superposed, rounded angular and 4-8 fx diam. in sur- 

 face view, together about 5-9 /jl deep, appearing laterally compressed in 

 section ; reproduction not seen. 



Mexico: Nayarit, dredged from 22 meters' depth at sta. 970 near 

 I. Maria Magdalena, Las Tres Marias, no. 39-656 (TYPE), 9 May 

 1939. 



ABODES J. Agardh, 1876 



Thallus foliaceous, entire or irregularly lobed, moderately thin ; struc- 

 turally showing a very loose medulla of slender branched filaments and 

 similar-appearing rhizoids ; cortex comparatively dense, of small rounded 

 cells ; tetrasporangia scattered ; cystocarps in small, scattered groups, im- 

 mersed in the medulla, with a well-developed filamentous pericarp. 



118 Cryptonemia decolorata n. sp. — Plantae parvae, irregulariter ramosae, ramis 

 3-12 mm latitudine, ad basim contractis; apicibus rotundatis, marginibus crispatis, 

 erosis, minute aculeato-dentatis; reproductione non observata. Planta typica in loco 

 dicto I. Maria Magdalena, Las Tres Marias, Mexico, legit W. R. Taylor no. 39- 

 656, 9 May 1939. 



