PLATYCRINID.K. — CYATHOCIUNUS. 61 



We have been unable to detect the slightest appearance of auxiliary side arms on the 

 column of tins species although Miller asserts they were of considerable length. The 

 figures 26, and 27, at page 86 of his Crinoidea, are not the side arms of any species 

 of Cyathocrinus, 26, being a small column, and 27, the column and side arms of a 

 Poleriocrinus. 



The base of attachment unascertained. 



Miller's principal figure of this species cannot be depended on, as he appears to have 

 taken the rays of the Taxocrinus longidaclijlus and placed them on the body of the 

 C. planus 



This Taxocrinus is figured in the Transactions of the Geological Society, vol. 5, pi. 3, 

 fig. 1, and which has often been referred to the C. planus. 



The specimen from which our enlarged figure 4, a, plate 7, js taken was found and 

 developed by Mr. William Morgan, of Clifton, Hotwells, to whose kindness we are 

 indebted for an opportunity of adding it to our illustrations. 



2. Species. Cyathocrinus geometricus. (Goldfuss.) 

 PL VII. fig. 5, a, b, c, d, e. 



Definition. — Dorso-ccntral plate quinque-partite, first series of perisomic plates five, 

 second series six, five of which bear the rays. 



Synonymes and References. 



Cyathocrinites geometricus. — Goldf. Pet. p. 180, t. 58,/. -5. 



Phill. Pal. Foss. Suppl. PI. 60,/. 41.* 



Formation and Localities. 



Devonian strata — Newton, South Devon ; and Eifel. 



The Dorso-central, and first series of perisomic plates of the C. geometricus are 

 I'aised conically in their centres, from which strongly-marked ridges radiate in sets of 

 four or five, the lines becoming sharper as they approach the margins of the plates, and 

 till they unite at the sutures with those of the contiguous ones ; the ridges of one plate 

 exactly fitting against the radiations from the plates adjoining it. 



The second series of perisomic plates consist of six, five of which bear the rays, these 

 latter plates are perforated near their centres, and grooved above for the passage and 



