Reviervs — WacJismuth 8^ Springer's Monograph on Crinoids. 319 



It is stated on p. 32 that this termiuology is the result of corre- 

 spondence with P. H. Carpenter, and that " Mr. F. A, Bather, in 1890, 

 also agreed to accept this termiuology with very slight modifications, 

 and applied it practicall}' in his earlier descriptions of British fossil 

 Crinoids, but renounced it in 1892, and proposed in its place a new 

 one." To remove the misapprehension to which such a presentment 

 of the case must give rise, it may be stated that the scheme of 

 terminology in question includes 86 terms ; of these I have formally 

 renounced seven, while I constantly use all the rest with perhaps 

 three exceptions, and five of the terms were actually proposed by me. 

 I am glad to be in better accord with the American authors than 

 they have been ware of. 



The expressions 'stem-joints' and 'arm-joints' are in common 

 use, no doubt; but this extension ot" the word 'joint' to the 

 segments separated by the joint, however admissible in the kitchen, 

 should not pass into scientific terminology, which should be, above 

 all things, precise and unambiguous. The arm-ossicles are now 

 generally called ' brachials ' ; the stem-ossicles may well be termed 

 ' columnals,' and the cirrus-ossicles ' cirrals.' As a natural con- 

 sequence of this loose use of the word 'joint,' we find Messrs. 

 Wachsmuth and Springer applying the term ' syzygy ' to the 

 brachials united by a rigid suture, rather than to the suture itself. 

 Such a usage is common, but that it is incorrect and unscientific 

 I have already shown ^ to the satisfaction of several leading writers 

 on crinoids, and among them Mr. Springer. As noted on p. 81 of 

 the monograph, " the term ' syzygy ' has also been used by some 

 writers for the immovable union of the nodal stem-joints with those 

 next below them" ; and to this use Messrs. Wachsmuth and Springer 

 object. It is true that the word was not used in this sense by 

 Miiller, who seems to have overlooked the structures in question, and 

 it is equally true that "radiated and dotted surfaces do not always 

 imply a ' syzygy ' " ; still, Miiller's definition is phrased in quite 

 general terms and not necessarily restricted to brachials, so that in it 

 there is nothing inconsistent with the extension to columnals. Such 

 extension leads to no ambiguity and saves the invention of yet 

 another set of terms. ^ 



The term ' centrodorsal ' is a never-ending source of trouble. 

 Our authors naturally do not confuse it with the absurdly-named 

 'dorso-central,' but they apply it to "the plate within the infrabasal 

 ring of the Marsupitidae." Now ' centrodorsal ' is the name of 

 that element in the skeleton of an Antedonid which is composed 

 of the infrabasals and the proximal columnal or columnals fused 

 into a solid cirriferous ossicle. We do not know the true relation- 

 ships of the plate at the aboral pole of Marsupites, but we know 

 that it does not comprise infrabasals and does not bear cirri. For 

 this reason I have proposed for it and for the similar plates in 

 Uintacrinus and Saccocoma the non-committal term ' centrale.' ^ 



^ " The term ' syzygy,' etc." : Zool. Anzeiger, xix, pp. 57-61, Feb. 3, 1896. 



^ See P. H. Carpenter, " 'Challenger' Report on Stalked Crinoids," p. 4, 1884. 



^ " On Tlintacrinus'''' : Froc. Zool. Soc. London, vol. for 1895, p. 997 ; 1896. 



