46 CIDAUIS. 



three, but in some but two ways : according to the running of these strings the stones 

 will easily cleave, but generally some one way rather than any other, which most com- 

 monly is agreeable to the helical running of the ridges of knots or furrows between them, 

 yet always obliquely to the axis of the stone, as is perfectly shown, tab. vi, fig. 9, which 

 represents the stone broken three several ways."* 



Lhwydd, in 1690, figured spines of the same species from the Coral Eag of Oxford- 

 shire. Parkinson, in his ' Organic Remains of a Former World,' gave a beautiful figure 

 of the test (PL I, fig. 9), which, it is but just to state, has been entirely overlooked, the 

 references to his work having been made only to the figures of the spines (PI. IV, figs. 

 15, 17); the first good figure of the test of this species therefore is, in reality, that of 

 Parkinson's. In the 'Petrefacta Germanise,' Goldfuss gave good figures of the spines 

 which he stated appertained to the test of Cidaris BlumenbacJdi ; and subsequent palaeon- 

 tologists, believing his statement, have nearly all followed his error. In the ' Description 

 des Echinodermes Fossiles de la Suisse,' M. Agassiz has figured the spines of Cidaris 

 jlorigeimna with the test of Cidaris BlumenbacJdi ; this is shown in the figure by the small- 

 ness of the granules of the scrobicular circle, in the smallness of the tubercles, and the 

 depth of the crenulations on the summits of the bosses, a group of characters which 

 belong to Cidaris Blumenbachii. In the ' Geology of Yorkshire,' Professor John Phillips 

 figured a test and spine of this species, under the name Cidaris Jlorigemma, from a Wilt- 

 shire specimen now in the Museum of the Yorkshire Philosophical Institution ; the correct- 

 ness of the determination then made has been proved by the tedious investigation which 

 was necessary to clear away the existing confusion relative to this species. M. Desor, in 

 his ' Synopsis des Echinides Eossiles,' restricts the name Cidaris BlumenbacJdi to the spines, 

 " aculei non testa," figured by Goldfuss ; but I cannot agree with my friend in this con- 

 clusion, because Mlinster gave the name to tJie test, about which there can be no mistake. 

 Goldfuss's error consisted in describing and figuring spines as belonging to this test which 

 appertained to another species; therefore I say "testa non aculei" in the synonym : as the 

 test is the body of the animal, and the spines are merely appendages of the same, it follows 

 that the name given by an author to a species must in every case relate to the major, and 

 not to the minor part described. Miinster's name, therefore, must still be given to the 

 German form ; which, as far as is at present known, has not yet been found in England. 

 M. Desor observes: "J'ai ete fort longtemps dans le doubte sur les limites de cette 

 espece, par la raison que les radioles et le test que Goldfuss a reunis, n'appartiennent pas 

 au meme oursin. C'est tout recemment que la decouverte de quelques echantillons avec 

 leurs radioles attaches au test, m'a permis de rectifier I'erreur dans laquelle j'etais tombe 

 avec d'autres paloontologistes. Le test figure par Goldfuss n'a rien de commuu avec les 

 radioles qu'il lui attribue ; il appartient a une autre espece decrite ulterieurement par M. 

 Agassiz sous le nom de C. Parandieri. Or, comme les radioles sont bien plus abondants 



* Plott's ' Natural History of Oxfordshire,' p. 125. 



