506 Howe: Phycological studies 



Fauchea Sefferi sp. nov. 



Thallus moderately thin (30-80^) and caftilaginous-mem- 

 branaceous when dry, cartilaginous and 135-320^ thick when moist, 

 cespitose-ascending(?), dichotomous, mostly 6-1 1 times forked, 

 spreading 7-12 cm., axils rounded or subacute, segments linear, 

 1-2.5 mm. wide, nearly uniform in width throughout or slightly 

 wider under the dichotomies, rarely concrescent, margins entire 

 (except for cystocarps), the terminal segments tapering, obtuse 

 or subacute, somewhat divaricate or patent; color a dull brownish 

 red; medullary layer of 2-6 irregular series of large elongate 

 nearly empty cells, these often irregularly compressed and folded, 

 55-1 37/x X 22-55^ in cross section (or reaching 240 X no/* in 

 basal parts), with occasional small interstitial cells, passing rather 

 abruptly to the subcortical layer of 1-3 series of smaller thick- 

 walled cells; cortical layer composed of distinct anticlinal rows 

 of 4-8 series of minute cells, these 3-9/* high, walls of cortical 

 cells soft, gelatinous, and confluent: cystocarps marginal, sessile, 

 nearly spherical, obovoid, or hemispherical, 0.5-0.95 mm. in 

 diameter. [Plate 31.] 



La Paz, Vives lie. 



Fauchea Sefferi is in a way intermediate between the Medi- 

 terranean F. repens (Ag.) Mont, and the Californian and possibly 

 northern F. laciniata J. Ag., but is amply distinct from both. 

 From Fauchea repens it differs in the evidently non-repent habit 

 of growth, in the thin and less cartilaginous thallus, in the narrower 

 segments (1-2.5 mm. vs. 2-8 mm.), in the smaller, more gelat- 

 inous-walled, more irregularly compressed and often folded cells 

 of the medulla, in the occurrence of occasional small interstitial 

 cells among the large cells, and in the more globose sessile cysto- 

 carps. From Fauchea laciniata, F. Sefferi differs in the dichot- 

 omous instead of palmate-laciniate mode of branching, in having 

 the principal segments narrower (often 1 cm. or more broad in 

 F. laciniata) and linear rather than cuneate, in the smaller strictly 

 marginal and non-coronate cystocarps, in the more gelatinous 

 cell walls, the usually more compressed cells of the medulla, etc. 



The specimens, dried under pressure, adhere fairly well to 

 paper except in the older parts. 



This species is dedicated to the memory of the late Dr. Pehr 

 Olsson-Seffer, editor of the American Review of Tropical Agri- 

 culture and professor of botany in the new Mexican University, 



