152 



GEOLOGY OF LA SALLE COUNTY. 



16. Cryplia^a iniindata. Probably a Dichelyma, 

 Floating- in water attached to submerged branches of 

 trees. 



13. Minium cuspidatum. Small, ^-1-inch, in 

 close tufts about the roots of trees, leaves oval or 

 obovate acuminate, serrate. 



18. Hypnum tamariscinum. Prostrate, branch- 

 ing- three pinnate, stem leaves with reflexed toothed 

 marg-ins, branch leaves lanceolate. On g-round and 

 old logs. 



H. Salebrosum. Prostrate 3-4-inch, irregularly 

 branched, leaves cordate acuminate, serrate. On logs. 

 Common. Foliag-e yellow g-reen, shining-. 



The careful student has here a considerable field 

 for investigation. There is much to be done in this 

 division, as we are aware that our work is but a beg'in- 

 ning-. 



HEPATIC.^:. 



The Hepaticae differ from the Musci in having no 

 axis of growth. They ^re without leaves, broad stems 

 rooting by the under surface, and spreading' from the 

 margin either by pushing- the wdiole border forward or 

 by sending out narrow arms. The flowering* organs are 

 not at all like those of the Musci, and the fruits are dif- 

 ferent. They are very common on the sandstone rocks, 

 often covering the whole surface for many square rods. 



Marchantia polymorpha. Frond g-reen, spreading-, 

 forked, sterile flower peduncled, lobed or rayed 

 above. Has many bud-like little cups on back of frond. 



Fimbriaria tenella. Frond thickened in middle, 

 purple on margin, flower or receptacle of four bell- 

 shaped involucres. Very common. 



