202 Messrs. Austin on new Genera 



these errors Mr. Phillips has repudiated the genus altogether, 

 and endeavoured to found a new one under the name of Gil- 

 bertsocrinus. We have carefully examined Miller's specimens 

 and compared them with the species from the Yorkshire lime- 

 stone which have been described by Mr. Phillips, and we are 

 quite convinced that they are generically identical with each 

 other ; it is therefore evident that either the genus Rhodocri- 

 nites or the Gilbertsocrinus must be suppressed. 



Though Miller was unquestionably wrong in his generic 

 definition, there can be no possible doubt as to the identity of 

 the fossils on which he founded his genus ; we therefore, on 

 mature consideration, think it just that the merit of priority 

 should be conceded to him ; and we trust that Mr. Phillips will 

 coincide in this opinion. 



If this principle is not to be recognised, every trifling error 

 of an observer may be taken advantage of, like a flaw in an 

 indictment, and the slightest mistake in his definitions be suf- 

 ficient to annul a long-established genus. In this manner we 

 might claim the right to rename the genus Platycrinites on 

 the plea that the dorso-central plate is undivided instead of 

 tripartite, as in Miller's generic character. 



Def. — Dorso-central plates five, quadrilateral, with a small 

 perforation at each of their inner angles, which, when the 

 plates are united, form the pentapetalous opening into the 

 column. 



First series of plates resting on the dorso-central five, hex- 

 agonal; second series five, heptagonal; these latter support 

 five hexagonal plates, which are succeeded by a like number 

 of pentagonal ones. On the upper edges of each of these 

 plates rest two lengthened hexagons, to which the ray-bear- 

 ing plates are attached. Between these latter are several pen- 

 tagonal and hexagonal plates. 



Mr. Phillips appears to consider the pentagonal plates be- 

 low the lengthened hexagons as the scapulae or ray-bearing 

 plates ; but this we consider erroneous, as all the plates w r e 

 have described as perisomic clearly envelope and form part of 

 the body, above which the rays become distinctly developed, 

 and were possessed of flexure, which their lower portions 

 must have been deficient in had they been as described by 

 Mr. Phillips. 



R. costatus, Austin, sp. 



Def. — Plates surrounding the body agree in number with 

 the generic type. A strong rib or fold extends from each of 

 the five angles of the dorso-central plates to about two-thirds 

 the distance between those points and the rays; they then 



