50 REVIEWS AND BOOK NOTICES. 
tion of Lingula, which has red blood, is reserved for discussion in 
a subsequent memoir. The digestive canal of the Brachiopods, 
as well as the circulatory system, does not compare well with 
those of the normal worms. 
“The anomalous features presented by some worms, in the 
absence of an anus, or the possession of a ccecal stomach, and 
the anterior termination of the anus, are fully repeated in the 
Brachiopoda. In one entire division of the ‘ag mage iat rene 
sented by Terebratula, the stomach terminates in a cecal s 
In Terebratulina the alimentary tract is closed posteriorly. Not 
has the slightest trace of an anus been detected in Thecidium, | 
Waldheimia, Rhynchonella, and several other genera that have 
been examined. In the very early stages of Terebratulina, I 
has 
Terebratulina, the alimentary tract pursues a direct antero- poste- 
rior course without convolutions, while in Lingula and Discina the 
anus terminates anteriorly on the right side. In Lingula, the in- 
testine makes a few turns, while in Discina it makes a single turn 
to the right.” 
The nervous system is much as in the worms, there being two 
lateral ventral cords, widely separated (in Lingula these lateral 
threads seem to be double and connected by commissures) and 
connected at the esophagus by ganglionic enlargements, which 
send off threads to the pallial membranes, and to the various mus- 
cles. The breathing organs of Brachiopods are contained in the 
pallial membrane, which is divided into two oblique transverse 
sinuses, apparently resembling the interior of the branchia of a 
worm. The genital organs are almost identical with those of 
worms, as may be seen by a study of Figs. 30-40. 
We now quote the author’s conclusions in his own words :— 
“In considering the assemblage of remarkable characters in 
the Brachiopods, we must recognize in them a truly ancient a 
and. consequently a synthetic, or comprehensive type. hus 
while we do not find them in all their characters ented any 
one group of worms, I have endeavored to show that all their 
features, to a greater or less degree, are shared by one or the 
th various pope of the Vermes, with one or two 
features shared by the Arthre 
It is important to remark in this connection that most of the 
ancient groups differ from present groups with which they are 
a Thus the Trilobites are widely unlike modern Crus- 
touk AS, Milne-Edwards and Van Beneden suggesting t their affini- 
AE DRS N EE MA A SE ENE eg NEE «i Sele ASA ae ot SESE E E eee ED 
