1885.] NATURAL SCIENCES OF PHILADELPHIA. 297 



as long as the Scytoderniata and Echinozoa of Leuckart are not 

 accepted, we think it unnecessary to establish a branch for the 

 Pelraatozoa. In principle, however, we agree with Carpenter, 

 and admit that the "Pelmatozoa " differ very essentially " in the 

 presence of a stem, and in the consequent departure from the 

 ordinary habits of an Urchin, Starfish or Holothurian. Whether 

 sessile or provided with a stem, the Crinoid lies on its aboral 

 surface instead of creeping about mouth downwards in search of 

 food" (Chall. Rep., p. 193), and they differ also in having no 

 locomotor organs in connection with the ambulacral system (Ibid., 

 p. 188). All this, however, we think is sufficiently expressed by 

 giving the Pelmatozoa the rank of a class, and placing them at 

 the end of the list. 



In our opinion there is no doubt that J. S. Miller proposed the 

 name Crinoidea to designate exclusively the brachiate Crinoids, 

 for he stated in his description (A Nat. Hist. Crin., p. 7), that 

 " there proceed from the upper rim of the cup-like body five artic- 

 ulated arms, divided into tentaculated fingers," and among the 

 species which he refers to them there is neither a Blastoid nor a 

 Cystid. Unfortunately, however, later writers have used the name 

 in a twofold sense, designating thereb}^ the class and one of its 

 subdivisions, until lately Zittel, in his Handb. der Palreontologie, 

 to remedy this, proposed the name " Eucrinoidea " for the 

 " Brachiata" i. e., Crinoidea, sensu .s£r.,and "Crinoidea" to take the 

 name of the class, an arrangement which has since been accepted 

 by De Loriol. To conform to Miller's idea, the new term should 

 have been given to the class, and not to the subdivision. But as 

 Leuckart had alread}' proposed the collective name " Pelmatozoa," 

 which has priority, and is a more appropriate term than Crinoidea, 

 Zittel's scheme need not be discussed. 



Carpenter has placed the Blastoidea and Cystidea on a level 

 with the Crinoidea, making all three distinct classes, a rank to 

 which we think they are not entitled. The three groups, accord- 

 ing to our views, are mere modifications of the same plan which, 

 so far as known, originated in the Cystidea, and of which the 

 Blastoidea and Crinoidea are mere offshoots. The latter group, 

 but especially the Blastoidea, are linked together with the Cys- 

 tidea by such eas}' transitions, that among the earlier types it is 

 difficult to draw any clear line of demarkation. We are unable 

 to point out a single character that is not found exceptionally in 



