134 THE BERMUDA ISLANDS. 



to show that the actinian fauna of the Bermudas has been de- 

 rived from that of the West Indies. 



EXPLANATION OF PLATES. 

 bc.=basa,l canal. en.=endoderm. 



c.=column wall. /r.=fronds. 



cm.^circular muscles. ra.=margin. 



cu. cuticle. >. tentaculiform fronds. 



d~ disc. sp.=sphincter. 



di.=digestive region of mesen- 



terial filament. sp 1 . lower sphincter. 



Eb. Ectoderm. .=tentacle. 



PLATE 10. 



1. Transverse section through the middle region of the 

 sphincter of Aiptasia sp. (?) X 350. 



2. Longitudinal section through the upper half of the column 

 wall of Aiptasia sp. (?) X 40. 



3. Transverse section through the outer edge of the longitu- 

 dinal mesenterial muscles of a specimen of Condyladis passi- 

 flora from the Bermudas. X 42. 



4. Longitudinal section through the margin and adjacent 

 parts of Dipladis Bermudensis. X 24. 



5. Longitudinal section through the margin and adjacent 

 parts of Oidactis fasciculata. X 21. 



6. Transverse section through the longitudinal mesenterial 

 muscles below the stomatodseum in Dipladis Bermudensis. 

 X 40. 



PLATE 11. 



1. Perfect mesentery of Dipladis Bermudensis. Natural size. 



2. Portion of transverse section of sphincter of Dipladis 

 Bermudensis. X 100. 



3. Transverse section of mesenterial filament of Zoanthus 

 flos-marinus just below the stomatodeeum. X 120. 



4. Transverse section of perfect mesentery of Zoanthus flos- 

 marinus slightly below the stomatodseum. X 50. 



