54 TASMANIAN BRYOrUYTA, 



Marchantiaceae. — The sporopliytes are free and borne 

 upon specially constructed branches. In the most ad- 

 vanced type these aje erect, umbrella-shaped, and carry 

 the sporopliytes on the under sui-face of the head. 



RICCTACEAE. 



The fronds usually form small dichotomously divided 

 rosettes on damp earth, or more or less cordate bodies 

 floating on water. The substance is thick in the middle, 

 tapering to the margins with a median groove on the up- 

 per surface. The ventral surface bears one row of scales 

 and numerous rhizoids. The upper surface is formed of 

 closely packed columnar cells. There are usually no pores, 

 but air cells are formed below the surface, which may re- 

 main small or may enlarge, become confluent, and eventual- 

 ly burst through the dorsal surface. The antheridia and 

 archegonia are immersed. The sporophyte matures within 

 the enlarged archegonium still sunk in the tissue of the 

 frond. All the contained tissue of the sporophyte develops 

 into spores ; no elators are formed. The spore tetrads re- 

 main attached till mature ; the exposed surface is vari- 

 ously sculptured; the rest is smooth. There are two 

 genera : 



RicciA. — Epidermis without pores; antheridia scat- 

 tered. 



KicciocARrus.— -Epidermis with distinct pores ; anthe- 

 ridia confined to the median furrow. 



KlCCIA-MlCH. 



The character of the family. 



In section as deep as broad tasmanica 



In section much broader than deep. 



Air spaces very narrow cras^a 



Air spaces broad wcynioutliiand 



Rircia faxmanira, St. — Fronds about 1 cm. long, 2 mm. 

 wide, simple or forked, apex retuse to nearly acute, upper 

 surface concave, with slightly broad median furrow ; sur- 

 face crystalline, pale green, margin joellucid, rather acute, 

 (entire or nearly so; chlorophyllous stratum dense, the 

 cells about 30 im- diameter, their exposed ends mamillate, 

 Init soon lost. Spores dark brown, 80 fi. diameter; mar- 

 gin narrow, the convex face with about 9 areolae, flat 

 faces with shallower areolae. A^cutral surface veiy con- 

 vex; in section as deep as broad. 



Mt. Nelson, Domain, Hobart. Probablv common 



