230 Rhodora [DECEMBER 
a compound word but he always wrote them as two separate words. 
Under genera so named he listed various species. For example he 
had a genus (p. 409) Pimpinella saxifraga and under it three species 
Pimpinella saxifraga foliis variis; Pimpinella saxifraga minor; and 
Pimpinella saxifraga foliis laciniatis. Sometimes, however, the 
specific name would not entirely follow the generic name. For 
example, he had a genus Lactuca Hortensis (p. 444) but the only 
species under it was named Lactuca vulgaris. Hill's ideas on nomen- 
clature are indeed very hard to follow, for he even had two genera of 
the same name, Lunaria, one belonging to the Cruciferae (p. 258) 
and the other (p. 530) being Botrychium. 
Most of Hill's double-headed generic names apply to genera which 
were given other generic names by Linnaeus, but there are a very 
considerable number of such names which are the earliest generic 
names for the genera involved published after 1753. If we use one 
of these names they all should be used. If we reject some we should 
reject them all. If weinsert a hyphen with some, so as to make them 
. compound words, we should insert a hyphen with them all. 
My own view is that all such names should be entirely rejected and 
that the rule promulgated by Linnaeus should be followed “ Nomina 
generica ex duobus vocabulis integris, ac distinctis facta, e Republica 
Botanica releganda sunt" (Philosophia Botanica Sec. 221). This 
is the rule whch has almost invariably been followed by botanists in 
practice. 
How important is the question involved, is shown by the following 
examples taken from Hill's work: 
(1) Speculum Veneris (p. 75) antedates Specularia Heist. (1763). 
(2) Bursa pastoris (p. 260) antedates Bursa Weber (1780) and 
Capsella Medic. (1792). 
(3) Raphanus rusticanus (p. 260) antedates Armoracia Ludwig 
(1757). 
(4) Gramen caninum (p. 496) antedates Agropyron J. Gaertn. 
(1770). 
(5) Gramen nemorosum (p. 502) antedates Juncoides Adans. (1763) 
and Luzula D.C. (1805). 
(6) Filix mas (p. 527) antedates Thelypteris Schmidel (1762): 
Dryopteris Adans. (1763); and Aspidium Sw. (1801). 
(7) Filix foemina (p. 528) antedates Pteridium Scop. (1760). 
One of Hill's double-headed genera, described by him on page 516 
