8o BULI.ETIN 5 350 



292 CRINOIDEA. 



tucky Asterial fossil. I shall now proceed to correct 

 the characters of that genus agreeably to the dis- 

 coveries of the ingenious Miller, in this family, 

 and to identify by name the species which I then 

 indicated. 



Pentremite. 



Column cylindrical, perforated ; segments arti- 

 culating by radiated surfaces, with cylindrical side 

 arms at irregular intervals : pelvis of three unequal 

 pieces, two pentagonal and one quadragonal : sca- 

 piil{Z large, very profoundly emarginate for the 

 reception of the tips of the radiating ambulacrae, 

 obliquely truncated at the extremities, each side, 

 for the reception of one side of a subrhomboidal 

 plate or interscapular : ambulacrcE five, radiating 

 from the summit, and terminating at the tips of 

 the emarginations of the scapulae ; each with a lon- 

 gitudinal, indented line, and numerous transverse 

 striae which terminate in a marginal series of pores, 

 for the transmission of respiratory tubes : summit 

 with five rounded openings (ovaries) and an an- 

 gulated central one (mouth and anus.) 



This singular genus is so remotely allied to any 

 other hitherto discovered, that I do not think it 

 can with propriety, be referred to any Family yet 

 instituted. By its columnar support it is related 

 to the Family Crinoidea, but the total absence of 

 arms and hands excludes it from that very natural 



[J. A. N. S., Phila., ist Ser., Vol. IV, 1825.] 



