442 SMITHSONIAN INSTITUTION 



CALEIDOCRINUS Waagen and Jahn 

 Plates LXXV, fig. p; LXXVI, fig. 24 



Caleidocrinus Waagen and Jahn in Barrande, Silur. Syst. Centr. Boheme, VII, pt. 2, 1899, PP- 106-112; 

 text-figs. 270-32, pi. 63. — Bather, Ann. and Mag. Nat. Hist. Ser. 7, Vol. VI, 1900, p. 111 ; Treatise an 

 Zoology (Lankester), 1900, p. 202. — Springer, Jour. Geol. XIV, 1906, pp. 485-486. — Zittel, Grundz, 

 Pal. I, 1910, p. 166. — Zittel-Eastman, Textb. Pal. Rev. Ed., Vol. I, 1913, p. 206. 



Professors Waagen and Jahn proposed this genus in 1899 upon certain specimens 

 occurring at Stage d 4 of the Second Fauna (Ordovician) of the Bohemian section, and 

 placed it near the Taxocrinidae of Angelin. Bather 1 in reviewing their work the following 

 year assigned this form to the Flexibilia Impinnata, considering it to be " a genus that 

 approaches the common ancestor of Ichthyocrinns and Taxocrhms." Through the kindness 

 of Professor Jahn, who made a special trip for me to the locality near Zahoran, I was able 

 to secure several specimens of C. multiramus in as good condition as they are usually found. 

 They occur in a schist, and the preservation is unfavorable to observation of some essential 

 characters. The authors say of this 2 : 



The skeleton and elements constituting the body of these sea lilies are changed into a ferric hydrate. 

 By reason of this change there exist only the negative impressions of half the calyx, which are filled with 

 a powder of ferric hydrate. 



They state in the explanations that the figures on their plate 63 are very defective 

 (" idealisees," — ■" entierement inexacte," — "qui n'est pas conforme a la realite"), and they 

 give other figures in the text partly from the same and partly from better specimens. Even 

 of these text-figures, however, they say on page 109 : 



The preservation of the interradius (ir, figs. 27&-31& in the text), and of the anal interradius (a, figs. 

 276-316 in the text), is so defective that if we can, in some cases, observe the position of the plates which 

 compose them, it is never possible to determine their number. 



I have six specimens in the condition described by the authors, viz., impressions in the 

 matrix filled with powder of iron oxide ; and one rather larger than usual in which, by rare 

 good fortune, the calcareous skeleton of the crinoid is preserved intact. I have also wax 

 casts of the specimens from which figures 1-2 and 11-14 on plate 63 of Waagen and Jahn's 

 work were made, most courteously sent me by Professor Perner of the Royal Museum at 

 Prague. In none of these have I been able to identify any interradial plates in the regular 

 areas ; and with reference to the text-figures of the authors, in which numerous small irreg- 

 ular plates are shown, I would suggest that in specimens preserved as these are it is impos- 

 sible to determine such structures with certainty. Many foreign bodies, even fragments of 

 arms, may become lodged between the rays which might, in the chemically changed condi- 

 tion of the fossils, be mistaken for small irregular plates. In my specimen with the external 

 skeleton preserved (PL LXXV, fig. 9) the radial and brachial plates are well defined, and 

 there is certainly no sign of any such plates meeting them between the rays. 



Commenting in 1906 3 upon the description of this genus by the Bohemian authors, and 

 upon Bather's reference of it to the Flexibilia, I said : 



The habitus of this form seems to me rather like that of the Inadunata, from which it is separated 

 only by the supposed interbrachial structures. 



At that time nothing was known of the character of the anal side. Reexamination of 

 my specimens with further preparation has brought to light the structure of this part in the 

 clearest manner, and furnishes the clue to the systematic position of the genus hitherto 

 entirely overlooked by all authors. As is indicated in most of Waagen and Jahn's figures, 



1 Annals and Magazine of Natural History, VI, 1900, p. 112. 



2 Barrande, Syst. Silur. Centr. Boheme, VII, 1899, p. 107. 



3 Jour. Geol. XIV, p. 486. 



