# 
476 Scientific Intelligence. 
between an Echinoderm larva and a Ctenophore; he shows that 
e 
8 to be the true anal opening, while according to Metschnikoff, 
i rt of an anal 
opening. He says it only acts to introduce water into the system, 
ations. 
may here recall former statements* concerning the affinities of 
the Ctenophorx, when describing some of the younger stages. It 
could only ke after a careful comparison of Ctenophorous and 
of | 
of plan might be obtained. The Ctenophore retain the perma- 
nently embryonic features of Echinoderm embryos, in which the 
s 
Pp 
; : m sponges 
_ With regard to the development from the earliest recognizable 
ears boa 
_ * Agassiz, Alexander. Ill. Cat. M. C. Z., No. 2, p. 12, 1865. 
