28 Ech 
ECHINODERMATA. 
Neu&jayr (1) argues that the ancestral form of the Echinothuridce must 
have possessed a firm test and complicated ambulacra, and that the 
family is immediately related to the Diadematidas , and shows no connec- 
tion with Palaechinus. 
Neviani discusses the phylogeny of Echinoderrns , and draws up tho 
following scheme of their descent : — 
Recent 
Neogenous - 
Eocene 
Cretaceous - 
Jurassic 
Liassic - 
Triassic 
Dyas - 
Carboniferous 
Devonian 
Silurian 
Cambrian - 
Archaic 
/\ A /\ A A 
5 
O 
6 s 
v 
CO 
© 
8 
K 
=o 
© 
<S 
s 
s 
^ o’ ^ 
K) 
a 
V 
^ 
V 
Annelids 
with 
trocho- 
spheres. 
Archelminthes 
( Balanoglossus ) 
Ccelomati 
Accelomi 
Gas treed. 
