KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 25. N:0 2. 63 



the bending över of the crown. The concomitant changes, however, do not take place at 

 quite the same råte as these connected with the anal plates. For instance, while in one 

 species of the stage c the fused basal enters into the stem-articulation, in another it will 

 not do so; or in the stage b, one species may have the basals fused, another separate; 

 similarly in c the two halves of the left anterior radial may be still touching or may be 

 completely separate; while in some forms of c and d the radianal and right anterior infer- 

 radial may have become anchylosed to the left posterior radial and the anterior radial 

 respectively. Consequently it is advisable not to lay so much stress on these concomitant 

 characters as Dr. Rixgueberg has done, but to take only the changes in the anal area as 

 diagnostic of the different genera. This is in accordance with the method generally fol- 

 lowed throughout the Inadunata. 



To forms of the earlier stages names have already been given, viz., (a) Castocrinus, 

 (b) Euchirocrinus, (c) Calceocrinus. By separating from Calceocrinus all species in stage 

 d, there will be four a>quipollent genera representing the four stages. As type of this 

 last genus I take the species called by Wachsmuth and Springer Calceocrinus ventricosus ; 

 the specimens examined by me were all from the Burlington Limestone and were labeUed 

 C. Wachsmuthi, C. ventricosus and C. dactylus. Now C. dactylus (which is either a variety 

 or a synonym) was taken by Ulrich as the type of his genus Halysiocrinus; it is pro- 

 bable therefore that it will save present heartburnings and future confusion to retain 

 this narae; and if any American pakeontologist should traverse the statement of Wachs- 

 muth and Springer that C. dactylus is a synonym of C. ventricosus, then the species Halysio- 

 crinus dactylus must be regarded as the type of this new genus, It is needless to repeat 

 that one cannot retain a single line of Mr. Ulrichs diagnosis. 



Before giving the needful diagnoses of the genera, it will be advisable to give the 

 terminology employed in the form of a table, by the side of that used by previous writers. 

 This should satisfy the collector, the curator, the student and the lecturer; only the spe- 

 cialist cares for argument. Since, however, the table is arranged in chronological order, 

 the gradual growth of correct opinions can be easily traced. (See next page). 



The revised diagnoses are as follows. 



Castocrinus, Rixgueberg. 



r. post. R* and r. ant. R* joined by ill-defined close suture; each abuts by one side 

 on adjacent large RR (1. post. R and ant. R respectively). x supported by r. post. R s only, 

 while r. ant. R*' supports IBr^ of r. ant. arm. R' and r. ant. R' separated one another and 

 from x by r. post. R s and r. ant. R s . 



Concomitant characters: BB unfased, all entering into articular facet of stern; 

 post. B and r. ant. B barely, or not at all, touching large RR. 1. ant. R s joined to 

 1. ant. R' by articulation (?) or loose suture, slightly projects above level of large RR. 

 Arms four. 



Type: C. furcillatus, W. R. Billixgs sp. 





