C84 HEPATIC^:. (LIVERWORTS.) 



2. R. Beyricllifina, Hampe. Frond oblong-linear, tliickcucd and bi- 

 fid at the apex, narrowly channelled above, dark purple beneath ; the margins 

 entire, ascending. Tennessee. 



3. K. bifurca, Hoffm. Frond suborbicuJar, pale-green; its divisions 

 wedge-shaped, 2-lobed at the apex ; lobes spreading, dotted, broadly channelled 

 above, purplish beneath, the thickened margins ascending. "North America." 

 (G.L.fr N. Si/n. Heptit. p. 600.) (Eu.) 



* # Frond with large air-cavities : terrestrial or aquatic. 



4. R. it Titans, L. Frond inversely heart-shaped, channelled above (3" - 

 5" broad), clothed beneath with long pendent rootlets in the form of linear-lan- 

 ceolate, serrate, purple fringes ; capsules in two rows, lengthwise of the frond. 



Floating on the surface of stagnant water. (Tab. 20.) (Eu.) 



5. R. flAitailS, L. Frond radiatcly expanding (I 1 or more in diameter) ; 

 divisions narrowly linear, repeatedly forking, nearly membranaceous ; at the 

 apex thickened, emarginate and cavernous ; capsule protuberant from the lower 

 surface of the frond. Floating on stagnant water. (Eu.) 



6. R. llltcSCCIlS, Schwein. Frond light-green, orbicular, I'-lJ' in di- 

 ameter; the divisions 6-8, linear, 2-3 times forking, channelled above, obcor- 

 date at the extremity, thickened, with whitish obliquely-ovate and appressed 

 scales beneath. On the ground, margins of ponds, &c. Fruit unknown. 

 (Sulliv. in Mem. Amer. Acad. n. ser. 4, p. 176, t. 4.) 



7. R. crystalline, L. Frond orbicular, 4" - 6" in diameter ; its di- 

 visions obcordate or linear-bifid, the margins subcrenate, the surface broken up 

 by deep pits, communicating with the air-cavities. Damp ground. Fruits 

 abundantly. (R. velutina, Hook. Ic. PL t. 149, is founded on sterile fronds of 

 No. 6, and fertile fronds of No. 7.) (Eu.) 



2. SPmEROCARPUS, Mich. ROUND-HEADED LIVERWORT. 



(Tab. 20.) 



Involucre sessile upon and continuous with the frond, obtusely conical or 

 pyriform, perforated at the apex, 1 -fruited. Capsule globose, closely invested 

 by the calyptra. Spores round, muriculate. (Antheridia in folliculose bodies 

 on the surface of separate fronds. Wilson.} (Name composed of <r</>cupop, a 

 sphere, and Kapyros, fruit.) 



1. S. Michelii, Bellardi. Frond orbicular, 3" -6" in diameter, lobed, 

 entirely concealed by the numerous aggregated inflated involucres, which are 

 about |' ; long, and 4-5 times larger than the capsules. (S. terrestris of authors.) 



Cultivated fields, South Carolina, Curtis, Ravenel. (Tab. 20.) (Eu.) 



SUBORDER II. AlVTIIOCEROTE^E. 



Terrestrial, froiidose annuals, with the fruit protruded from the upper 

 surface of the frond. Perianth none. Capsule pod-like, mostly 1-2- 

 valved. Columella filiform. Elaters none or imperfect. 



