94 CORRESPONDENCE. 
Pilularia globulifera, Z.—Streatham, “prope fontes medicatos.” (R. Syn. iii: 
136. In a pit on the left-hand, about a hundred paces above the Hill 
) 
House. 
EQUISETACER. 
Equisetum Telmateja, Ehrh., E. arvense, L L.—H. Are both common on the 
Weald clay. 
For some additions to the lists of introduced. plants in the Flora 
(Appendices A and B), see papers by Mr. Britten in ‘Journal..of Bo- 
tany, Vol. I. p. 375, and the ‘Botanists’ Chronicle, 1864, p. 20: I 
gathered Impatiens parviflora on a bank at Mickleham in 1861, and 
Melton parvifiora in cornfields at Merton. 
CORRESPONDENCE. 
The Law of Priority in oe 
‘ambridge, January 6, 1864. 
No o person can read the valuable text of the new rp of ‘English Botany” 
without seeing that Mr. Syme has ideas about nomenclature not altogether in 
accordance with the rules followed by most botanists. As in general these 
ideas do not infringe very greatly or injuriously upon law, no formal objection 
has been raised to them. But in the recently published No. 13 there is 
an instance of departure from legal usage of a serious kind ; and itis defended 
in a footnote by laying down a rule which is contrary to former decisions. ^ Tf 
this new law were accepted many of the recognized generic names would pro- 
bably have to be altered, and thus much confusion would be introduced into 
botanical nomenclature. The case in question will be found in page 128 
of volume ii., where Spergularia (Pers.) i is adopted as the name of the genus 
Lepigonum of Fries; and the note in defence of this act—* The name Lepi- 
Mr. Syme's reason for adopting Spergularia as of Persoon, and as a generic 
name. 
It is true that some excellent botanists have used the same nomenclature as 
Mr. ride but they, in most cases, tacitly express their belief of Spergularia 
the claim of priority, as used generically, over Lepigonum. | De 
Candolle les down a definite law to regulate such cases. "He says (‘ Théorie 
Elémentaire,’ p. 266) that when we divide a zenus, the portions of it which do 
not continue to bear the old name ought, if the groups were considered 
as genera by the ancient botanists, to retain their ancient names; thus Poly- 
