CLASSIFICATION IOI 



Miller, although not in very clear terms, took as the chief basis of his 

 general classification the mode of union between stem and calyx and between 

 calyx and arms ; and upon this character he subdivided the Crinoidea into four 

 primary groups comprising nine genera, all but two of which were at the same 

 time proposed by himself. These were (i) Articulata: Apiocriniies, 

 Encrinit.es, Pentacrinites; (2) Semiarticulata: Poteriocrinites; (3) Inar- 

 ticulata: Cyathocrinites, Actinocrinites, Rhodocrinites, Platycrinites; and 

 (4) Coadunata: Eugcniacrinites. The first of these included most of the 

 Mesozoic and Recent crinoids; the second and third the then known Paleozoic 

 genera of what are now the Camerata and Inadunata. His primary groups, 

 except the first, have not survived ; but his generic names are among the classics 

 of crinoid literature, and have been utilized for the designation of well- 

 grounded family divisions. 



The so-called classification of Johannes Muller has been given a promi- 

 nence in subsequent treatises somewhat disproportionate to its merits, due no 

 doubt to the great and deserved 1 reputation of this distinguished man as an 

 anatomist. The structure and embryology of the various types of the Echino- 

 derma attracted his earnest attention, resulting in a series of memorable re- 

 searches which formed both a foundation and a model for all future work of 

 that kind. He did not undertake the systematic study of the Crinoidea, nor 

 did he propose a formal classification; but incidentally, in connection with an 

 anatomical study of the West Indian stalked crinoid, " Pentacrinus caput- 

 medusae" (Isocrinus asteria), he assigned family names to certain forms or 

 groups as they came up for consideration. The first of these (under the same 

 name) was essentially the Articulata of J. S. Miller, with the Comatulae 

 added — containing crinoids with free rays rising above the joining membrane. 

 The second, Tessellata, without any very accurate definition, included Miller's 

 Semiarticulata and Inarticulata plus some additional genera of similar type, 

 and also Marsupites. These two embraced all then known crinoids except three 

 genera, each of which he thought should be placed in a different family. For 

 Saccocoma he proposed "Costata"; for Haplocrinus, " Testacea " ; while 

 Holopus was left without other designation. He considered the " stalked 

 crinoids without arms, as the Pentremites and Sphaeronites " to form two 

 families, but did not propose for them any additional names. Muller gave a 

 list of genera as examples of his family Tesellata, and it is interesting to note 

 that among the Paleozoic crinoids included by him and by J. S. Miller in their 

 respective families there is not a single genus belonging to the order Flexi- 

 bilia, which forms the subject of the present work. 



Bronn * in i860 adopted the three divisions, Articulata, Tessellata, and 

 Costata, upon the authority of Johannes Muller (though without any credit to 



1 Klassen und Ordnungen des Thier-Reichs, p. 228. 



