Miscellaneous. 283 
two thin slices of mica the size of a postage-stamp, my colleague 
at Budapest sent me what he believed to be Pemphigus zee-maydis. 
As I thought, he was mistaken ; the insect which he discovered on 
the roots of the maize is a Tetraneura, since the hind wings have 
only one nervure instead of two, as the species of the genus Pem- 
phigus should have. Moreover, the size, shape of the antenn, and 
absence of hairs on the abdomen proved that it was Vetraneura 
ulmi and not Tetraneura rubra, of which I had discovered the sub- 
terranean habitat in the preceding year, and which lives at the roots 
of the dog’s grass. 
Here, then, we have the complete history of the biological eyo- 
lution of a second Aphis of the elm, discovered, so to speak, simul- 
taneously in France and Hungary, and which had already been 
elucidated by Prof. Kessler, of Cassel, placed now beyond doubt. 
In the train of Phyllowera quercus, Anopleura lentisct, and Tetra- 
neura rubra, of which | made known the migrations from one 
species of oak to another, or from the roots of grasses to the 
mastic-tree and the elm, we have Tetranewra ulmi, which migrates 
in June from the elm-galls to the roots of the maize, and which 
returns in October in the pupiferous form, bringing forth the sexual 
individuals upon the trunks of the elms. 
As to Pemphigus zee-maydis, its gallicolous form (that is to say, 
the foundress and emigrant phases) still remains to be discovered.— 
Comptes Rendus, July 16, 1883. 
Elevated Coral Reefs of Cuba. By W. O. Crossy *. 
Mr. Crosby describes in this paper the elevated coral reefs of 
Cuba, and draws from them the apparently well-sustained conclusion 
that they indicate a slow subsidence during their formation, and 
hence, further, that Darwin’s theory of the origin of coral islands is 
the true theory. The lowest reef-terrace of the northern side of the 
island has a height of 50 feet, and varies in width from a few rods 
to a mile; it was once plainly the fringing reef of the shore. The 
second reef-terrace rises abruptly from the level of the lower toa height 
of from 200 to 250 feet, and bears evidence of having been of like 
origin with the lower. The altitude of the third reet is about 500 
feet ; and the fourth has a height east of Baracoa, near the Yumuri 
River, ‘‘of probably not less than 800 feet.” These old reef- 
terraces extend, ‘ with slight interruptions, around the entire coast 
of Cuba; and in the western part of the island, where the erosion 
is less rapid than further east, they are the predominant formation, 
and they are well preserved on the summits of the highest hills. 
Mr. Alexander Agassiz states that the hills about Havanna and 
Matanzas, which reach a height of over 200 feet, are entirely com- 
posed of reef-limestene.” 
* Proc. Boston Soc. Nat. Hist. 
