WR THE NEW EVOLUTION ^^^^ 



^ body worm-like, unsegmented, with a spacious 

 undivided body cavity not connected with the 

 excretory or generative organs; living on the 

 bottom in sand or mud; sexes separate 



Priapuloidea 

 f^ with a complicated generally retractile ciliated 

 apparatus in connection with the mouth, used in 

 the gathering of food; size very small; abundant 

 asexual reproduction 

 ^ ciliated apparatus consisting of cilia about the 

 mouth in the form of a ring, or in lobes or vari- 

 ous patterns; asexual reproduction by unfer- 

 tilized eggs only; sexes separate and usually 

 very different; solitary, though sometimes 

 social 



ROTIFERA 



^ ciliated apparatus consisting of a circular or 

 horseshoe-shaped crown of ciliated tentacles 

 with the mouth in the middle; always with 

 asexual reproduction by budding, sometimes 

 also by the formation of "statoblasts" or by 

 fragmentation of the larvx; usually both sexes 

 in the same individual; almost always colonial, 

 forming plant-like colonies 



POLYZOA 



d?- with definite traces of radial symmetry (superposed 

 upon the bilateral) in the nervous system, the 

 digestive system, or the anterior end 



VeRMI FORMES 



c^ individual animals entirely, or almost completely, radi- 

 ally symmetrical, like a flower, with tentacles or other 

 processes about the edge of the large central cavity, 

 which is bounded by solid walls 

 d} body divided into quadrants, with two axes, a long and 

 a short, at right angles to each other; eight rows of 

 vibratile plates formed of fused cilia; two tentacles or 

 none; no stinging cells; never colonial; no asexual 

 reproduction; mesoderm present 



Ctenophora 



[170] 



