66 PLATTCRINID.E. CYATHOCRINUS. 



imbedded. Though this might lead to error, it is surely preferable to multiplying species 

 on insufficient evidence. 



These remarks are equally applicable to most other genera, as well as to the genus 

 Cyathocrinus. 



So great has been the confusion in this genus that of the twenty four or twenty five 

 species described by various Authors, we consider only seven of them to have been 

 established on a proper basis. 



Of the four species of crinoids figured and described by Miller as Cyathocrini, only 

 one belongs to Itie genus. His C. Tuberculaius has been included in our genus Euryale- 

 erinus, his C. rugosus has been remo\'ed to the genus Crotalocrinus, and we have also 

 found it necessary to transfer his C. qninquangularis to another genus. 



The Cyathocrinus macrocheirus of Mr.GrifFiths Carboniferous Limestone of Ireland is 

 clearly not a Cyathocrinus but it is a Poteriocrinus. 



The C mequidactylus of the same author is merely a small specimen of the C. Planus, 

 all its specific characters perfectly agreeing with those of that crinoid. 



Another species, the C.distans, which Professor Phillips has figured in the Paloeozoic 

 Fossils, PI. 59. Figure 49* is merely a fragment consisting of two columnar joints. — 

 This specimen may possibly appertain to the C. geometricus, or it may be a portion of 

 an auxiliary side arm, or a column of some one or other of the He.vacrini, for as yet we 

 have no knowledge as to the form and structure of the the columns of that genus. The 

 same remarks will apply to the C. mcgastylus; the C, ellipticus; the C. variabilis; and the 

 C. noclulosiis, of the same Author. 



The appearance presented by the specimen which Professor Phillips has named C. 

 nodulosus, is perhaps the eflfects of weathering, for we have seen the side arms of an 

 Actinocrinus assume the same tuberculated exterior, even in situations where others 

 associated with them have remained unaltered. 



The very imperfect fossil for which Miller proposed the name of Cyathocrinus ahhrev- 

 iatus in the appendix to his work, is so doubtful in character that we have omitted it 

 altogether, it may appertain to the C. planus, or some other known species of Cyathocrinus 



The C. ornatus of Phillips' Geology of Yorkshire appears to be the Platycrinus 

 striatus of Miller. And not one of the so called Cyathocrini of Murchison's Silurian 

 System properly belong to the genus. 



The C. Pentagonus oi Goldfuss, will probably be found to belong to some species of 

 Pentacrinus, to the columns of which it bears a close resemblance. 



It has already been observed that the genus Cyathocrinus is not found in the Silurian 

 rocks, for the encrinites of that system are distinct in species and mostly if not entirely 

 in general from those of the Devonian and Carboniferous groujis. In the Devonian rocks 

 the genus Cyathocrinus first appeared on the stage of life, but the species inhabiting 



