42 Illinois State Laboratory of Natural History. 



7. F. pilosa Tayl. Thallus bifurcate or dichotomous, 

 2 6 mm. long, subspatulate or narrowly obcordate, obtuse, 

 emarginate, the margins thin and hyaline, repand-undulate, 

 divergently striate and distinctly porose above, squamous be- 

 neath; scales large, fuscous purple, paler toward the apex, not 

 reaching the margin; carpocephalum rather small, hemispheric, 

 3-4-fruited, umbonate and minutely verruculose in the center 

 when dry, somewhat barbulate beneath at its juncture with the 

 peduncle: peduncle 2.5 3.8 cm. high, tapering from a stout 

 base, naked, fuscous brown, shining; inner involucre rather 

 large, 8-12-cleft; spores large, rugose-cristate; elaters short 

 somewhat obtuse, bispiral; androecium in a distinct lobe next 

 the fertile one, circular, immersed. (Marchantia pilosa Wahl.. 

 M. gracilis Web. f., F. gracilis Lindb.) 



Hab. Br. Col. (Macoun), Greenland (Vahl). (Eu.) 

 Bib. Syn. Hep. p. 557 ; Hep. Europ. p. 157. 



F. PALMERI Aust. (Torrey Bulletin VI, 47), found by Dr. 

 Palmer in Gaudalupe Island off Lower California, may occur in 

 So. California. 



XI. AITONIA FOKST. 



Carpocephalum deeply 1-4-lobed, the lobes small, ascend- 

 ing, discrete, their apices merging into ample, vertically bi- 

 valved involucres. Peduncle emerging from a pit in the back 

 of the thallus, involucrate. Involucres subcompressed, ovoid, 

 erect, 1 -fruited, opposite and concealing the lobes of the recep- 

 tacle, vertically or horizontally dehiscing, 2-valved. Inner 

 involucre wanting. Calyptra lacerate and persistent. Capsule 

 globose, nearly sessile, somewhat horizontal, rupturing at the 

 apex by an irregular vertical line. Spores enveloped in a trans- 

 parent, rugose membrane, many angled, smoothish. Elaters of 

 medium length, bi-quadrispiral. Androecium disciform, muri- 

 cate-papillosc, immersed in the apex or the middle of the thallus. 

 Thallus rigid, thick, indistinctly porose, continuous or innovat- 

 ing from the apex, or proliferous from the costa underneath. 

 Named for William Aiton, a Scottish botanist, 1731-93. 



