MONOGRAPH OF THE EXISTING CRINOIDS. 



271 



It is a matter of great interest that where cirri occur they are definitely seg- 

 mented, and also appear in defmitely localized positions, just like the limbs of the 

 arthropods taken as a whole, to which, as structures, they are allied. They also 

 resemble the limbs of arthropods m being specialized anteriorly, though the proximal 



FlO. 312. 



^^^^^^^^^^CJ^^^ 



F,r, -ilMW -312 Cirri from a specimen or Aniedon difida from England (camera lucida drawing by the actboe). 



3.1 mRi^ROMTsPECmK/o^ MEDTERRANEA FROM NAFLES (CAMERA LUODA DRAWING BV THE AUTHOR, 



cirri do not diflfer much from the distal and earlier; it is possible, however, to regard 

 the elongate marginal cirri which never assume the adult characters, such as are seen 

 m the species oUIeliometra,Pro>mchocrinus, Anthometra, Fhrometra or Solarwmetra 

 for mstance, as tactUe organs, distantly suggesting the antennae of the arthropods. 



