HAMBACH ANATOMY OF THE GENUS PENTKEMITES, ETC. I45 



Contribution to the anatomy of the genus Pentrcmites, 

 with description of new species. 



By G. Hambach. 



One of the many interesting classes of fossils belonging to our 

 subcarniferous fauna is that of the Blastoida^ and in it the genus 

 Pentrefuitcs is of especial interest, not only on account of the 

 abundance of the specimens which appear in some of the strata, 

 but equally, if not more so, on account of their excellent state of 

 preservation and the entire absence of living representatives. 



They have occupied the attention of many able writers, and 

 form, according to current opinion, a connecting link between 

 the true Crinoids and the Echinoids^ with perhaps a little more 

 resemblance to the latter. The conclusions arrived at by the 

 study and examination of more or less suitable material in regard 

 to the anatomy of the calcareous shell forming the calyx, as well 

 as of the functions assigned to the different organs preserved in 

 it, are by no means unanimous ; and as the specimens are in most 

 cases represented by insufficient or incorrect figures, the external 

 aspect of some has been made to differ so much from that of oth- 

 ers as to cause the creation of new genera or of separate groups, 

 although the pieces forming the calyx remain the same in number 

 throughout the whole genus, and one who allows considerable 

 latitude, yet may not justify this separation, and may regard the 

 differences as specific rather than generic. 



It, therefore, becomes almost a necessity to recapitulate the his- 

 tory of this genus in order to determine the true condition of the 

 fossil in question. Having had an opportunity to study a large 

 and excellent material, partly in my own possession, and num- 

 bering several thousand specimens in almost every stage of pre- 

 servation, I may be able to contribute something to our present 

 knowledge of this curious being. In describing the same I shall 

 adopt the old terminology given by Roemer, for various reasons: 

 (i) the old names denote more clearly the forms and conditions 

 of the object to which they are applied — as "radial pieces," etc, ; 

 (2) as already mentioned, the specific characters and number of 

 pieces remain the same throughout the whole genus ; (3) they 

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