﻿Howe: New American Hepaticae 191 



Africa, Asterella linearis (Steph.)* and Asterella Preussii (Schiffn.)t 

 and one from Persia, Asterella Persic a (Steph.), % which all differ 

 (judging from descriptions alone) in being dioicous, while A. Persica 

 evidently has a thicker thallus, being described as subsemicircular 

 in transverse section, its scales are more prominent, the carpo- 

 cephalum is 5-6-locular, etc. ; A. linearis has geminately appendicu- 

 late scales, a highly papulose capitulum, and an almost fusiform 

 pseudoperianth ; and A. Preussii has scales attenuate at the apex 

 into a very long hyaline seta, thicker thallus margins, a purple 

 peduncle 25-30 mm. long, etc. The spores and elaters of these 

 three exotic species are undescribed. The color and markings ot 

 the spores in this genus afford valuable characters, in the Amer- 

 ican forms, at least, for distinguishing species and these particulars 

 have commonly failed to receive the attention that they deserve at 

 the hands of authors. Spores that are nearly opaque in water 

 often show the surface-sculpturing very clearly on examination 

 in glycerine. 



Exp'anation of Plated. 



Plate 336. Scapania (?) heterophylia. M. A. Howe. 



I. An entire plant, 4 the natural size, 

 and 3. Opposite views of a portion of the stem, showing the often three-ranked 



leaves, X 1 S 



4. Dorsal view of stem and leaves, X J 5- 



5. Ventral view of the same object, showing an unlobed underleaf, X *5- 



6. The leaf with lobes "a" and "a*" already shown in figures 4 and 5. 



7. A typical underleaf, X I 5- 



8. Outline of a deeply lobed leaf, X *5- 



9. Apex of a branch of the same plant from which figures 4 and 5 were drawn; 

 leaves here distichous, X 1 S- 



10. The leaf " d " from the foregoing, X I 5- 



II. Ventral view of a leaf, X ^ 



12. Cells from near base of leaf, X 2 44- 



13. Cells from the apical margin of one of the upper leaves, X 2 44- 



14. Paraphyse- from axils of leaves, X 2 44« 



15. Cross section of the stem, X 3 2 - 



Plate 337. Riecia trichocarpa. M. A. Howe. 



I and 2. Portions of the plant, natural size. 



'17111 



4. End of a thallus lobe from fig. 1, with ostioles and a sporogonium, X IO - 



* Fimhriaria linearis Steph. Engler's Bot. Jahrb. 20: 302. 1895. 



f Funbriaria Preussii Schiffn. Steph. /. c. 303. 



% Fimbriaria Persica Steph. Hedwigia, 33 : 7. 1894. 



