position and arrangement of the numerous fragments in my possession, and 

 to make with these (as it were) disjointed skeletons. These fragments which 

 presented me often with characters, that in more perfect specimens are par- 

 tially concealed, pointed out that something more than the bony portion (or 

 rather internal bonelike concretions of these animals, which must in this 

 respect be considered as analogous in structure to the Star-fish) had been 

 preserved, and bad sustained the process of petrifaction, and that traces of 

 muscular covering investing them were clearly observable. I was thus led to 

 an inquiry into the myology of these beings, which combined with the former 

 observations, aided in obtaining a more satisfactory knowledge of their 

 economy, and a more correct determination of their genera and species. I 

 was much pleased, when on a subsequent examination of the Pentacrinus 

 caput medusae (the only recent, and very rarely occurring species) I was con- 

 firmed in the correctness of the conclusions which T had deduced from the 

 inspection of the fossil fragments. The course of these researches convinced 

 me that the animals described by Mr. PARKINSON as Encrinites and Pen- 

 tacrinites, and by M. LAMARCK and M. CUVIER arranged under the single 

 genus, JBncrinus, would readily and properly form a distinct and peculiar 

 family, comprehending several genera and species. The new order thus 

 constructed, requires to be separated from the POLYPI NATANTES of M. LA- 

 MARCK an order to which its members were most unhappily referred by that 

 author, although they possess neither of the characters indicated by that name, 

 being in truth widely different from Polypi, and instead of floating freety, being 

 generally fixed to one spot. They form the natural transition to the stellerida; 

 family, but especially to the genera ALECTO of Dr. LEACH, and MARSUPITES 

 of GIUEON MANTELL,, Esq. 



As the Zoological principles adopted in this Work coincide generally with 

 those of M. LAMARCK, but yet in many instances, exhibit modifications of them, 

 which would appear inadmissible were his opinions implicitly embraced ; it will 

 materially assist us in forming a clear view of the place which is assigned to 

 the present order in the scale of animated nature, and illustrate the observa- 

 tions which it may be necessary hereafter to introduce; to subjoin in this 

 place a brief review of that part of the system of this author, (who proceeds 

 from the lower and most simple to the more complicated and perfect animals) 

 which includes his lowest classes, those namely, which precede and accom- 

 pany that in which he places the genera of which we are now entering 

 upon the description. We must begin then by observing, that according to 



