112 Mr. F. A. Bather on the 



Several specimens were distributed by Barrande under the 

 manuscript name, Echinoencrinites multiramus. The present 

 authors place it in or near the Taxocrinidse of Angelin, 

 which is as much as to say that it belongs to the Flexibilia 

 Impinnata. It is of interest as being older than any Flexible 

 genus hitherto known, and the interest is enhanced when we 

 see how its structure accords with its age in the eyes of the 

 evolutionist (Fig. 5). The Flexibilia Impinnata of the 

 Silurian rocks fall into four main groups, which may pro- 

 visionally be regarded as families and named Ichthyocrinidae, 

 Taxocrinidae, Calpiocrinidse, and Sagenocrinidae. The two 

 latter are clearly more specialized than the two former and 

 have a larger proportion of representatives in later rocks. 

 Both Ichthyocrinidae and Taxocrinidse have isotomous arms, 

 which may abut, and in some Ichthyocrinidae even interlock, 

 by their sides. Taxocrinidse have a few interbrachials, of 

 which the proximal is the largest ; their anals form a well- 

 defined vertical series resting on the posterior basal. The 

 Ichthyocrinidae have no interbrachials, and their simplest 

 genus, Ichthyocrinus, has no anals. Now Caleidocrinus 

 resembles Ichthyocrinus in the absence of anals from the radial 

 circlet and in the isotomy of its arms, which are, as in that 

 genus, sometimes inrolled at their distal ends ; but it re- 

 sembles the Taxocrinidse in the presence of interbrachials 

 with occasional intersecundibrachs, which, however, are all 

 very small and irregular. The authors believe themselves 

 able to distinguish an anal interradius by the presence of 

 3 vertical rows of interbrachials instead of 2. But since 

 these interbrachials lay in a flexible integument, a greater or 

 less expansion of the arms would of itself expose more or 

 fewer interbrachials. However this may be, we have in 

 Caleidocrinus a genus that approaches the common ancestor 

 of Ichthyocrinus and Taxocrinus, although an important point 

 of divergence, and one by no means primitive, lies in the 

 minuteness of the basals. All the specimens except one are 

 assigned to C. multiramus, which has two primibrachs. The 

 remaining specimen, having 3 primibrachs, is made another 

 species, C. Barrandei. The authors' argument is not without 

 force, but " the possibility that more abundant material of the 

 two species may disclose yet other distinctive characters " 

 seems to me far from the probability. 



We return to the consideration of those members of the 

 third fauna which are referred either with doubt or certainty 

 to genera previously known. The first is called Calpiocrinus? 

 bohemicas, or sometimes Catyiocrinus ? ? ? bohemicus (Fig. 6). 

 The latter mode of expression is preferable, for, as the authors 



