386 p. HERBERT CARPENTER. 



plate and basals of a Crinoid no representatives in the apex of a 

 Starfish or Urchin ; while the subanal plate of an Urchin is un- 

 represented in the Crinoid, and the striking resemblance between 

 the calyx of a Crinoid and the apical system of an Urchin or 

 Asterid goes for nothing. I still believe, however, that the 

 relations of the plates to the enterocoel sacs of the larval Echi- 

 noderm are fundamentally more important than the position of 

 the particular plate which comes into ultimate relation with the 

 water- pore. The genitals of an Urchin or Asterid and the 

 basals of a Crinoid are all developed spirally around the right 

 (abactinal) enteroca3l ; while the orals of a Crinoid or Ophiurid 

 appear in a similar spiral around the left (actinal) enterocoel. 

 Until Ludwig can show good reason for neglecting these facts, 

 and can explain away the various inconsistencies involved by his 

 theory, I shall continue to regard the abactinal system of a 

 Crinoid as homologous with that of Urchins and Starfishes. 



