AMOKG SIMPLE SAECODE ORGANISMS. 401 



the results of a eareful study of this remarkable little rhizopod 

 (fig. 6). The nearly globular shell is prolonged into a short neck, 

 which carries the pseudopodial orifice. It thus allows an oral and 

 aboral pole to be distinguished, while the orifice being a little to 

 one side gives to the shell a slightly bilateral symmetry. 



Fig. (5. 



Microgromia socialis. 



A, a colony in its extended state ; some of the individuals seen in longitudinal 

 fission. B, a colony in its compact or cystophrys state ; some of the individuals 

 at a distance from the main heap. C, formation of a swarm-spore ; the portion 

 which is to become a swarm-spore has advanced towards the anterior end of the 

 shell. D, further stage in the formation of a swarm-spore ; the portion which 

 is to become a swarm-spore escaping through the orifice of the shell. E, one of 

 the swarm-spores now complete and free. (After Hertwig.) 



LINN". JOURN. — ZOOLOGT, VOL. XIII. 34 



