1885.] NATURAL SCIENCES OP PHILADELPHIA. 291 



until 1879 (Rev. i, p. 30). At that time we also proposed the 

 name " Stomatocrinoidea," and made both groups subdivisions of 

 the "order " Crinoidea, of equal rank with Blastoidea and Cystidea. 

 To the Palaeocrinoidea we referred the earlier brachiate Crinoids 

 in which mouth and food grooves are subtegminal or hidden from 

 view ; to the Stomatocrinidae the Mesozoic and recent Crinoids in 

 which mouth and food grooves are exposed upon the disk. Both 

 groups were admitted by Carpenter and Etheridge, Jr., in 1881, 

 but thej^ changed the name Stomatocrinoidea into " Neocrinoidea" 

 because, as they stated, our name was " long and cumbersome," 

 and they were " by no means sure that some of the Palseocri- 

 noids had not an external anal opening." We might, no doubt, 

 successfully controvert the right of Carpenter and Etheridge to 

 change our name, which had priority, and which was sufficiently 

 defined to be recognized, until they proved satisfactorily that the 

 name-giving characters were inconsistent or incorrect. This view 

 of the case was evidently taken by De Loriol, who in his late work 

 (Paleont. Francaise, tome xi, p. 43) placed both names in equal 

 rank. We hold there is not a single Palseocrinoid known in 

 which either mouth or food grooves are exposed, nor a " Stomato- 

 crinoid " in which they are closed, and this we still regard as one 

 of the best distinctions between the two groups. We, therefore, 

 wish to have it understood that, in accepting Carpenter's name, 

 we do not give up our original position, but yield to the preferable 

 name. 



The Crinoidea were subdivided by Joh. Miiller into " Crinoidea 

 Articulata " and " Crinoidea Tessellata," the latter including the 

 Inai'ticulata and Semiarticulata of Miller. Midler's definitions of 

 his groups were extremel} T vague, but we may conclude from the 

 names and from the genera which he referred to them, that they were 

 based upon a supposed difference in the mode of union of the first 

 radials with the plates which they bear. Among the Tessellata, 

 however, we find Foteriocrinus which has highly developed articular 

 facets, not only between radials and brachials, butalsoat the bifurca- 

 tions of the arms. Zittel, who adopted Midler's divisions, defined 

 the calyx plates of the Tessellata as " Unbeweglich durch einfache 

 Nathe verbunden ; " those of the Articulata as " durch gelenkartig 

 ausgehohlte und gewijlbte oder ebene Nathflachen vei'bunden." 

 But nevertheless he refers to the Tessellata the Ichthyocrinidae, 

 in which the radials are united with one another by ligament and 



