11 
Tuiiicata. In the so-called Jiiyozoa or Polyzoa tlie only motion of the liody possible 
is that through cilia of various lengths, and this suggested the name CUioiioda. I 
am perfectly aware of the great disadvantage of coining characteristic names from the 
consideration of a single organ in a large division of tlic animal kingdom, such as 
the Mollusca represent, but no system -will ever enjoy advantages without consoling 
itself with at least some disadvantages. And if wo really look upon the names of 
the other classes noiv in general use, I do not think that of Cihopoda in any way 
less correct or less suggestive than that of Brachiopoda or Cephalopoda. 
Still the question may he put, whether it is at all desirable at the prese'ut stage 
of our knowledge to introduce a new name for a class of which Zoologists arc in doubt 
whether it belongs to Molluscs or to M'orms. Doubts of that kind may and will arise, 
the more our detailed knowledge of the structm’c and dcvelo 2 )mcnt of the various 
groxrps of animals increases, but the difference in, or deviation from, the general tjqxc 
may be weighed very differently by some authors tlian by others, according to 
their ideas of the absolute distinction of the divisions of the anunal kingdom, 
or of the gradual transition from one to the other. I cannot see any conclusive 
reason for 3Ir. Morse’s assertion that the Ciliopods, as well as the Brachiopods, 
ought to be removed from the Mollusca, and classed mth the Vermes. The 
question regarding the Brachiopods was lately discussed at length by Dali in 
the American Journal of Conchology, vol. 7 , p. 39 ; and much that has been said 
regarding the latter class applies equally to the Ciliopods and Saccopods. Indeed, 
from some recent observations of Prof. Allman* on the anatomy of a new 
Ciliojxod genus, ]lhahdoi')leura, it ajijxcars that some CUiopoda, at least, are moiqxho- 
logically even more closely related to the Pelecypoda than to the Brachiojxoda. 
I do not for one moment wish to deny the imixortance of embryological studies 
as bearing ujxon om* zoological system, but it must be borne in mind that our 
classification refers, in the first instance, to the full grown and well developed 
animal, not to the embryos or to abnormities, or occasional deviations from the type. 
Su 2 >posing we took the embryos of man, of a tiger, a bird, a turtle, and a lizard, 
and wished to arrange our classification according to then’ relations and differences, 
what woidd become of our system of the Vertebrata ! 
* Quart. Jour. Jlic. Sc., New Ser., No. 33, 1809, p. 02. 
