38 Illinois State Laboratory of Natural History. 



Capsule oblong-globose, dehiscing by 4-6 irregular valves, dis- 

 tinctly pedicelled. Spores minute, muriculate. Elaters parie- 

 tal,* very long, straight, attenuate at both ends, bi-trispiral. 

 Androecium short peduncled, paleaceous underneath the mar- 

 gin (in the young state ciliate). Thallus large, thin, soft, with 

 a slight costa, dichotomous, continuous or articulate at the 

 apex, with or without pores, usually with hair-like rootlets 

 scattered over the entire under surface. Gemmae wanting. 

 Named for B. C. Dumortier, a Beigian botanist, born 1797. 



1. D. hirsuta Nees. Dioecious; thallus 5 15 cm. long, 

 1.3 2 cm. wide, thin, deep-green, becoming blackish, plane and 

 entire on the margins, exareolate and naked, or sometimes with 

 a delicate, coarsely reticulated, closely appressed, cobweb-like 

 pubescence above, hirsute and esquamulose beneath; carpo- 

 cephalum many-fruited, convex, its margins like those of the 

 involucres, closely setulose, the upper surface sparingly so; pe- 

 duncle rather long, chaffy at the apex, slightly involucrate at 

 the base, otherwise naked; capsule wall composed of very long 

 thick cells containing broad rings or bands; andrcecium on a 

 short peduncle, setulose over the entire upper surface; fruit 

 rare. (Marchantia hirsuta Swz.) 



Hob. Faces of moist calcareous rocks, S. C. (Ravenel), Easton, Pa. 

 (Porter), La. (Feathermari). 



Bib Syn. Hep. p. 543, 790. 

 Delin. Sulliv. Mosses U. S. t. VI. 

 Exsic. Hep. Bor.-Amer. No. 130. 



IX. CONOCEPHALUS NECK. 



Carpocephalum conic-mi triform, membranous. Involucres 

 5-8, tubular, 1-fruited, suspended from the apex of the pedun- 

 cle, coherent with the interior surface of the carpocephalum. 

 Inner involucre wanting. Calyptra persistent, campanulate. 

 2-4-lobed at the apex. Capsule oblong-pyriform, dehiscing by 

 5-8 re volute segments, ^pedicelled. Spores muriculate. Elaters 

 short, thick, bispiral. Androecium disciform or oval, sessile 

 near the apex of the thallus. Thallus dichotomous, copiously 



* Adhering to the inner face of the capsule wall. 



