54:. 



5. Absence of a posterior aorta. 



6. Kidjieys glandular tlirouf^^oiit their extent, 'vvithout 

 internal partitions, or coTnmuni cat ions between them. 



?. Genital glands opening into the pericardial ex- 

 tremities of the kidneys. 



8. Pleural ganglia still distinct frpm the cerebral, 

 and pleuro-pedal connectives arising by distinct origins from tJie 

 cerebro-pedal . 



9. Visceral ganglia little developed, much smaller 

 than the cerebral." 



It is not my intention to enter into theoretic consid- 

 erations until my studies on other numbers of tlie group are more 

 co:nplete, but so far as Yoldia limatiila is concerned the fore- 

 going statement is not accurate. 



Of Pelseneer's numbered statenents, numbers 2, 5, and 

 7 are wholly wrong and I can do no better t2ian refer the reader 

 to t^at has already been said under these heads (see pages /-J,^/ 

 and J^). Number 8 I have not been able to confirm. 



The theoretic value of tlie gills is, for the present, 

 rendered doubtful inasmuch as tiey ha^'-e a special f^anction that 

 accounts for their shape and structure. Here there remains the 

 choice of two views, viz, that they have been modified from a 



