"During a study of a Carboniferous blastoid fauna from Grassington, Yorkshire, over a thousand blastoids were collected, of which 45 individuals were referred to the genus Codaster. This study has left no doubt that the two species Codaster acutus McCoy and Codaster trilobatus McCoy are synonymous. Codaster trilobatus (in the sense of McCoy's original description), is an old age form, its characteristic feature only being attained by a minority of long-lived individuals. Codaster acutus McCoy is the valid name, being the first described, and is also the type-species for the genus. In order to supplement observation on these specimens, biometrical methods have been employed to study the relative growth of the height, diameter, and number of hydrospires."