— 74 — 
Oxymitra Bisch. in Lindenb. Syn. Hep. Eur. 124. 1829. 
Tessellina Dumort. Comm. Bot. 78, pro parte minima et atypica. 1822. 
Rupinia Corda, in Opiz, Beitr. Naturgesch. 650. 1829. Not Rupinia 
L. f. Suppl. 69. 1781. 
Pychoscenus Lindb. Ofv. Sv. Vet.-Akad. Forh. 19 : 606. 1863. 
Oxymitra paleacea Bisch. loc. cit. 
Riccia pyramidata Raddi, Opus. Sci. Bologna 2 : 350. pi. 15. f. 3. 
1818. Not Riccia pyramidata Willd. (excl. syn.) Mag. Bot. 2 4 : 9. 
' 1788. 
Tessellina pyramidata Dumort. Comm. Bot. 78, pro parte atypica. 1822. 
Hep. Eur. 165. 1874. Schiffn. in E. & P. Nat. Pflanzenfam. I 3 : 15. 
f. 5. 1893, K. Mull, in Rabenh. Krypt.-Fl. Deuts. 6 : 217. /. 140 , 
141. 1907. 
Oxymitra polycarpa Bisch. loc. cit. 125. 
Rupinia pyramidata Corda, loc. cit. Steph. Bull. Herb. Boiss. 6 : 759. 
1898. 
Oxymitra pyramidata Hiiben. (excluding certain synonyms) Hepaticol. 
Germ. 24. 1834. Bisch. Nova Acta Acad. Leop. -Carol. 17 : 1049. 
pi. 70. f. II, III. 1835. Lindenb. Nova Acta Acad. Leop. -Carol. 
18 : 491. pi. 35. 1836. Nees, Naturges. Eur. Leberm. 4 : 382. 1838. 
Pycnoscenus pyramidatus Lindb. loc. cit. 
Tessellina has been rejected by Stephani (loc. cit.) as a nomen nudum, but 
it was hardly that under any of the modern codes of nomenclature. The orig- 
inal Tessellina Dumort., and the Tessellina as it remained until after Bischoff 
had established his Oxymitra, rested on the following words: 
“2. Tessellina, fruit sortant par une fente; on doit rapporter a ce dernier, 
la R. reticulata poir. non sw. = Tessellina coriandri nob. et la R. pyramidata 
willd. = Tessellina pyramidata, nob.” 
The first of these two species is manifestly the plant now known as Corsinia 
marchantioides and it is scarcely open to doubt that it was Micheli’s conspicu- 
ously reticulate or tessellate figure of the thallus of Corsinia and Micheli’s diag- 
nosis, Riccia major, Coriandri sapor e, foliorum superficie veluti tessellata that 
suggested to Dumortier the generic name Tessellina. It is obvious that under 
the American Code the first of these two species is the type of the genus Tessel- 
lina and the provisions of the Vienna Rules 10 may possibly be interpreted as 
pointing to the same conclusions. 
Riccia pyramidata Willd., the second of the two original species of Tessel- 
lina, is now generally conceded to have been intended for some true Riccia with 
elevated antheridial ostioles. Willdenow’s rather detailed description is drawn 
10 “Art. 45. When a genus is divided into two or more genera, the name must be kept and 
•given to one of the principal divisions. If the genus contains a section or some other division 
which, judging by its name or its species, is the type or origin of the group, the name is reserved 
for that part of it.” 
