- 
Astronomy. 67 
synonym, on the grou nd that it is not the Astrea pid Dana. 
ae latter identification is, however, correct, and was made after a 
reful examination of Dana’s type. ‘which had the septa and walls 
cucdueably-w orn. Ellis and Solander are given as the authority 
for Meandrina jectonere Verrill, but their name was Madrepora 
clivosa. The name Astrea should be adopted instead of Fuvia 
(p. 75), for A. ndieadods was made the type of the genus b 
Lamarck in 1801 when it was first proposed, and he mentioned 
only one other species (A. radians) which he referred to a second 
division of the genus and which now Biron — type of the genus 
Siderastreea, belonging among the Fun We see no reason 
whatever for supplanting the oldest name coe diss igs rt bore (8. 
rian) - a later one, as has been done by Mr. Pou 
ong the genera now first made known as paodginy to the 
fauna of Florida and the West Indies are Fungia, Dendrophyliia, 
cata and Colangia, the last a new genus allied - of 
angia = 
Ill. AstTRoNoMY. 
1. On the mean motions of the four outer Planets. (Extract 
from a letter of Prof. Bensamin Purrce to Prof, Newton, dated 
ni nee 
“anna 
sn" + BnVi— nv 
Of the fixedness of the first of these equations I have no doubt; 
and am almost equally certain of the second, but feel rather more 
doubt concerning the third. Their reception involves a laborious 
n* Laamaie 719 (1+4) 
ni = 44001'-8054(1-+44) 
ni — 15428'°1822(1+4) 
mili 7871'°5215(1+4) 
in which 4 is a correction to be ascertained after the revision of the 
theories, 
