52 : REVIEWS AND BOOK NOTICES.. 
ties with the Arachnids. Tetrabranchiate Cephalopods are widely 
separated from the Dibranchiate Cephalopods. Crinoids are 
widely unlike modern Echinoderms. In other words, among the 
Mollusks, Echinoderms and Crustaceans are ancient types widely 
different from the modern types with which they are correlated. 
So in worms we should expect to see ancient types, while pa 
senting a high organization, yet differing from e? esent groups to 
which they are unquestionably related. ‘And fro 
the high complication of structure of the Arathi. Wie. 
opods, “Tetrabranchiates, and other ancient types, 
it would seem that in their culmination in ancient 
times they had i same relation to animals living 
then as the higher groups of present times bear 
to their ee As to the more ancient forms 
of Brachiopods, it is probable with them, as with 
other groups, that their lower members were soft- 
bodied, and the argument that has been urged, as 
militating against Darwin, that animals of high 
complication of structure occur in the older 
ney tt becomes valueless, when we consider that 
e lower forms of their respective groups are 
more often soft-bodied, and that complicated forms 
of earlier times wn -a Sea forms of 
preexisting gr 
To sum up the aks eh :—ancient Cheetopod Alciope Cantrainii. 
worms culminated in two parallel lines, on the m, inner mouth, 
one hand in the Brachiopods, and on the other, in oui ae ype ee 
the fixed and highly cephalized Cheetopods. The orifice of dito; b 
an rab of the Brachiopods, having been at- : 
in more ancient times, a few degraded features are yet re- 
tained, whose relationships we find in the lower Vermes; while 
from their later divergence the fixed 
Fig. 40. 
close allied to present free Chæto- 
. pod 
S. 
pods, 
Sabella, Protula and other 
Chætopods 
Segmental He P SIN 
Of ditto; e extemal orifice ar ae Aside from the great interest of 
orifice of ditto; 
A Resp naa a, accessory vesi- the memoir, the skilful and concise — 
manner in which the facts, — many 
discovered by the author himself after the most patient ee 
which would in —— commend the work fa SYR, one —4 
o 
fe mental organ of 4 
tie cephalized Annelides are more — 
| i 4 * eo eal in as modern (later) pees 7 
