1885.] NATURAL SCIENCES OP PHILADELPHIA. 299 



Pelmatozoa. Carpenter admits on p. 191 the close affinities 

 between the Cystids and Blastoids, but the Crinoidea he takes to 

 be a well-defined group " b}^ having segmented arms attached to 

 the radials, contrary to the Cystids and Blastoids in which there 

 are either no arms at all, or structures of an entirely different 

 nature from those of the true Crinoids." We have already 

 directed attention to Caryocrinus and Porocrinus as having well- 

 developed arms, similar to those of Hybocrinns, and also calicine 

 pores. If we were to make the division between Crinoids and 

 Cystids upon the arm structure, and did not make the calicine 

 pores the principal distinction between those groups, Ave would 

 also have to place among the Crinoidea Comarocystites, which 

 has not only segmented arms but even pinnule-like appendages. 

 Neither could we leave out Glyptocystites and Pleurocyxtites, in 

 which the arms are long and lined with well-defined covering 

 plates. 1 



Burmeister (Zoonomische Briefe, Leipzig, 1856, vol. i, p. 243) 

 divided the " Crinoidea " into Anthodiata, among which he in- 

 cluded the Cystidea and Blastoidea, and " Brachiata " with 

 Tessellata, Articulata, Costata and the genus Holopus. This 

 arrangement, leaving out the Costata, which probably are not 

 Pelmatozoa at all, seems to us a very good one, and we find it 

 convenient to adopt his divisions as " subclasses," substituting, 

 however, for Burmeister's name Brachiata, Miller's older name 

 Crinoidea. This enables us to discriminate between Palaeocri- 

 noidea and Neocrinoidea on the one side, and Cystidea and 

 Blastoidea on the other, which, as we have stated, are more 

 distinct from one another than the groups which we place under 

 them. To make the Anthodiata and Crinoidea separate classes, 

 on a level with the Urchins, would give to them too much im- 

 portance. We doubt if Carpenter will claim them to be anj'thing 

 like as distinct groups as the Ophiurids and Starfishes, which 

 by some systematists were regarded as mere subgroups of the 



1 The Cystidea have never been properly defined. They form in our 

 opinion an assemblage of several groups of equal rank -with the Blastoidea. 

 S. A. Miller pointed out in the Cincinnati Journal of Xat. Hist., Dec. 1882, 

 the Licbinocrinoidea and Ajjelacrinoidea as orders of tbe Crinoidea ; the 

 latter name, however, must be changed to '•Edriasterida,'' as this has 

 priority. It was proposed by Prof. Huxley in his classification of animals, 

 London, 1869, p. 130 (Carpenter). 



