54 F. A. BATHER, CRINOIDEA OF GOTLAND. 



ii pleated fringe; even when they do look like cirri, they are attached to tlio steni by no 

 articular facet. The articular surfaeéa of the stem-ossicles do not show the characteristic 

 inarkings of Herpetocrinus. It is therefore impossible to refer these stems to the presenl 

 genus. I merely mention them in tliis place because they suggest that the bilateral sym- 

 metry of the Herpetocrinus steni may have been evolved througli the ancestors of the 

 genus having adopted sonie sueh mode of attaehment. This, however, renders the en- 

 crusting root of H. scolopendra still more difficult of reconciliation with the two rows 

 of cirri and with the coiled steni. 



This species was not figured by Angelin. 



Locality: Follingbo, (t*). Not known ont of Gotland. 



CALCEOCRINIDiE. 



Inadunata Monocyclica, in which a, bilateral symmetry along the left anterior radiua 

 and right posterior interradius has been superinduced in conjunction with the bending of 

 the crown on the steni in sueh a way that the right posterior interradius lies along the 

 stein; with the left anterior, right posterior and right anterior radials eompound; with 

 anal x shifted över the right posterior radius, usually into the right posterior interradius, 

 and supporting a massive tube; with three, rarely four, arms, of which two are as a rule 

 peculiarly modified and bear armlets or pinnules. 



This Family has long been a puzzle both to Systematists and Morphologists; it is 

 therefore not surprising that a study of much fresh material should necessitate importanl 

 changes. 



First, however, it is necessary to discuss the Synonyniy, which, for two distinct 

 reasons, is exceptionally complicated. The first reason is the ordinary one, that different 

 naraes have been given at different times to the same genus: the second reason is the 

 difHculty of determining adequate diagnostic characters for the various forms belonging to 

 this family, a difficulty that lins hitherto been exaggerated by misapprehension of the funda- 

 mental structure. 



The history of opinion and of nomenclature may be simply traced without prejudice, 

 but the grounds upon which the genera are here established will be better understood 

 after their morphology has been explained in a new light. 



The first discovered fossil belonging to this Family was deseribcd in 1852 by Prof. 

 James Hall 1 ) under the name Calceocrinus : the fossil was rightly recognised by him as 

 a basal circlet with sutures obscured, but, being unable to give a diagnosis, he refrained 

 from attaching a specific name to the specimen figured. Thus a genus was founded with 

 no t)'pe-species, and when, eight years låter, Prof. Hall 2 ) proceeded to describe various 



') Palaeont. New-Tork II, p. 352, IM. LXXXV, fig. 5, »'>. 



2 ) 1 3t.h Rop. N. Y. State Cab. Nat. J list., p. 122, Albany, 1860. 



