Lower Pahvozoic CrinoiiU of Bohemia. 



105 



JJi'i/ricfiocrinus liuntilis, the sole species oi' the genus, 

 coiiK's tVom the linn-stoiu! f2 of Koiieprus *. Only the cup 

 is j)reserveJ (Fig. 1). It consists of the following i)riin;iry 



■ analio 



Fig. 1. — Analysis of tlie cup oi Bci/richocn'uu.^ /niwilis, outlines copied 

 from Waafrcn and Jalin, and about twice nat. size. Inter- 

 braohials (illJr) and anals are sh.aded from right to left; 

 inteisecundibracbs (illBr) from left to right ; intertertibrachs 

 vertically. 



elements : 3 biisals, 2 large and 1 small ; 5 radials, which 

 apjiear to abut laterally by short sides, except in the posterior 

 interradius; 2 iixcd ])rimibrachs in each ray, the first being 

 hexagonal except in the right and left posterior rays ; 2 fixed 

 seeundibrachs in each half-ray ; 2-4 fixed tertibrachs, of 

 which tlie last is axillary and bore the free quartibrachs. 

 The secondary elements of the cup are : 5-10 interbrachials 

 arranged in 4-6 horizontal zones, the proximal intcrbrachial 

 resting on the steep shoulders of two adjacent radials and 

 coming very near to the basals ; in the wider anal inter- 

 radius are about 14 interbrachials (anals), of which the 



cup is an abuse." It is therefore perplexing to find the autliors per- 

 sistently nsing the term in the sen.^e they here deny to it. Tlie fact is 

 that the word cait/x has so often been used for the dorsal cup, that our 

 attempts to define it otherwise seem bound to fail. The adoj>tion of 

 the term tluca, as used by Ilaeckel, for the whole case or test con- 

 taining the ciiitral organs of the animal, seems the most rational escape 

 from the difliculty. 



The symbols and ti-rminolo^jy of the present paper differ but slightly 

 from these explained in the Ann. i^- Mng. Nat. Ilist. ser. ('», vol. ix. p. 6f, 

 Jan. 1M»l\ The ni>menclalur<' luid (•la.';silicati"n follow I'art 111., 'J'he 

 Echintiderma, of ' A Treatise on Zoology,' edited by K. liav J.,ankester : 

 London, 1900. 



* Oddly enough, the authors have adopted for the Bohemian names a 

 .spelling difl'ereiit from that hitherto employed in the ' Sy^1l'lne 8ilurien.' 

 Their reasons, tbou^dj iu)t given, are probably good enough to warrant 

 me following them m this article. 



