A. Crane—Classification of the Brachiopoda. 321 
These discoveries Dr. Beecher now confirms and emphasizes by 
dividing Terebratellide into three well defined families: 1. Dallinine, 
2. Magellaniing, and 3. Megathyring (= Argiopine), comprising adult 
genera which indicate the larval conditions of both the higher groups, 
each of which ultimately terminates in a form superior to that of the 
adult Terebratallia. 
The first boreal sub-family receives its designation from the new 
genus Dallina, in which Dr. Beecher has placed the old familiar 
form of Terebratula (W. septigera, Loven), paying a just tribute to the 
excellent work of Dr. W. H. Dall, the doyen of the recent Brachio- 
podists of America. It would, perhaps, have been more graceful to 
have renamed this northern species after the Norwegian conchologist 
who first made known the successive stages of the loop development 
in the boreal type, and to have associated Dr. Dall’s name with the 
new genus Terebratalia founded by Beecher, with Terebratella 
iransversa, G. B. Sowerby, as type, for it is with the metamorphoses 
of the Terebratelle that the American brachiopodists’ work is more 
intimately connected. The genera Macandrevia, King; Dallina, 
Beecher; FEudesia, King; TZerebratalia, Beecher; Trigonesemus, 
Koenig; Lyra, Cumberland; Laqueus, Dall; Muhlfeldtia, Bayle; 
Kingena, Dav.; Ismenia, King; and Platidia, Costa; are placed in 
the sub-family Dallinine of Beecher. 
The second sub-family receives the name of Magellaniine from 
the culminating type Magellania (Wald.)venosa, Sol.; and the genera 
Terebratella, D’Orb.; Magasella, Dall; Mayas, Sowerby; Megerlina, 
Deslongchamps ; Bouchardia and Kraussina, Davidson, are included 
therein. ; 
The third sub-family Megathyring, Dall, comprises only the recent 
Megathyris (=Argiope) Cistella, Gray; Gwynia, King; and the 
Liassic Zellania, Moore. 
The lower genera in all the sub-families do not complete the series 
of development, but the higher forms pass through all the successive 
grades. It would seem therefore that both branches of the Terebra- 
tellide originally sprang from some minute form allied to the in- 
significant atavistic Gwynia of existing oceans and Tertiary deposits. 
Palzontologists should therefore turn their attention to this small 
but interesting survival of the ancestral terebratelloid type, which 
doubtless lived before the Jurassic period, when several well-marked 
genera were in existence. Hxact knowledge of the stage of loop 
development attained by many of the so-called Waldheimia, of the 
old terminology, is still lacking. This department of science lost in 
Hugéne Deslongchamps an enthusiastic and capable investigator, 
a philosophical student of the living forms, and well acquainted with 
the genetic distribution and succession of the Jurassic species. His 
work is evidently known and appreciated in America. 
Dr. Beecher considers that the radical stock of the Terebratelloids 
early branched off in two directions. Changing environments ac- 
celerated development and thus genera were prematurely launched 
on the sea of life, and in their turn perpetuated arrested types of 
inferior grades of structure, while others again passed up into higher 
DECADE III.—VOL. X.—NO. VII. 21 
