4-JO SMITHSONIAN INSTITUTION 



This Irish species is remarkable for the great extension of the primary brachials, in 

 which it is unique among the Flexibilia ; and among the Onychocrinus type it stands alone 

 in having ramules which apparently branch to the inside. The specimen is so imperfect, 

 however, that we are not very certain as to the exact plan, and the intervals appear to be 

 irregular. That it had an interbrachial system is shown, but this was evidently quite limited, 

 and in this respect the affinities of the species would be rather with the r amnio sus group. 



Types. Science and Art Museum, Dublin, Ireland. 



Horizon and locality. Middle part (Calp) of the Carboniferous limestone; Ballin- 

 trillick, Bundoran, County Donegal; also County Sligo, and Florence Court; Ireland. 

 According to the lists of fossils given in M'Coy's Carboniferous Fossils of Ireland, pp. 238, 

 251, the stratigraphic position of this species is in the second, or Middle (Calp), of the 

 three divisions into which he and other authors subdivide the Carboniferous limestone of 

 England and Ireland. The first, or Lower, division is that known as the Lower Carbonifer- 

 ous, or Mountain limestone; and from it, and the so-called Carboniferous slates or shales 

 below it, have been derived most of the Carboniferous species of crinoids and blastoids 

 described by the British authors. These include such well known forms as Amphoracrinus 

 gilbertsoni, Actinocrinus triacontadactylus, Gilbert so crinns calcaratus, etc., which corre- 

 spond with the crinoid fauna of the lower part of the American Lower Carboniferous, viz., 

 the Burlington and earlier rocks. Therefore the present species must be assigned to a 

 relatively later stage, whereby it will be comparable with those of the ramulosus group. 



