Ser. RHODOSPERMEiB. Fam. Rhodomelacea. 



Plate CCXXII. 



AMANSIA PINNATIFIDA, iiarv. 



Gex. Char. Frond flat, midribbed, pinnatifid or proliferous, transversely 

 striate, membranaceous ; the membrane formed of hexagonal cells, of 

 equal length, arranged in obliquely transverse lines or striae, destitute 

 of cortical cellules. Fructification : 1, ovate or globose ceramidia, 

 containing a tuft of pear-shaped spores ; 2, simple or branched, mar- 

 ginal or superficial stiehidia, containing tetraspores in a double row. 

 — Amansia {Lamour.), in honour of M. Amans, a French phycolo- 

 gist. 



Frons plana, costata, pinnatifida v. prolifera, transverslm striata, membranacea ; 

 lamina ex celluUs oblotifjis hexahedris aqualibus oblique transversim ordinatis 

 confiata ; celluUs corticalibus nullis. Fruct.: \ , ceramidia ; 2 , stiehidia mar- 

 ginalia V. superficialia, tetrasporas biseriatas foventia. 



Amansia pinnatifida ; frond alternately bi-tripinnatifid, pinnse and pin- 

 nules linear, constricted at base, inrolled at apex, with a very slender, 

 monosiphonous, articulate midrib ; areolations linear-oblong, hexa- 

 gonal, in transverse zones, alternately those of one zone shortening, 

 those of the following zone lengthening from the midrib to the mar- 

 gin; fruit unknown. 



A. pinnatifida; fronde alterne bi-tripinnatifida ; laciniis lacinnlisque linearibus 

 basi constrictis apice inwlutis casta tenidssima monosiphonia articulata per- 

 eursis ; areolis linear i-oblonc/ is hexagonis transversim zonatis, iis alterius zones, 

 e casta ad marginem gradatim alterne breviaribus et langioribus ; fructu ignato. 



Amansia pinnatifida, Harv. Alg. Austr. Exsic. n. 119. 

 Hab. King George's Sound, always infested by Membranipora delicatis- 



sima, Bsk., common, JF. H. H. 

 Geogr. Diste. South-west of Australia. 



Descr. Fruit a small disc. Frond 6-8 inches long, and as much in the ex- 

 pansion of the branches, linear in every part, from 1 to 1| lines wide, seve- 

 ral times distichously pinnatifid. Brunches alternate or secund, their 

 pinna3 and pinnules 2-4 lines asunder, erecto-patent, narrowed at base, with 

 infle.xed margins and inrolled obtuse apices, traversed by a very slender, 

 unicellular, articulated midrib. The membrane is composed of a single plate 

 of elongated, hexagonal, longitudinal cellules, arranged in zones trans- 

 versely across the lamina ; these zones are alternately difllerent, the cells in 

 one zone diminishing in length from the costa to the margin, those in the 

 other diminishing from the margin to the costa. No fruit has yet been 



