BJaiTISH FOSSILS. 



Decade IY. Plate IX. 



CARDIASTER GRANULOSUS. 



[Genus CAEDIASTEK. Forbes (1850). (Sub-kingdom Kadiata. Class Echinoder- 

 mata. Order Echinoidea. Family Ananchytidae.) Body cordate, tumid or depressed ; 

 lateral ambulacra having tbe upper part of their avenues slightly dissimilar ; all the 

 ambulacra convergent on the vertex, the anterior one lodged in a strongly marked 

 sulcus with angulated sides. A fasciole passing beneath the anus and continued on the 

 sides. Apical disk elongated, and composed of four perforated genital and five perforated 

 ocular plates. Tubercles perforate, their bosses crenulate. No dental apparatus.] 



Diagnosis. A. ambitu regulariter cordato, dorso depresso, tuhercuUs 

 primariis anticis co7ispicuis. 



Synonyms. Spatangus granulosus^ Goldfuss, Pet. Grerm. p. 148, 

 pi. 45, fig. 3. (1826-33.) Desmoulins, Tabl. Syn. p. 410. 



Spatangus cordiformis, Woodward, Geol. Norf. p. 50, pi. 5, fig. 6. 

 (1833.) 



Holaster granulosus) Agassiz, Prodr. Ech. p. 16. Agassiz and Desor, 

 Cat. Pais, des Ecliiii. in Ann. des Sc. Nat. 3d ser. vol. viii. p. 27. 



Holaster equalis, Portlock, Geol. Pep. Londonderry, &c. p. 355. pi. 17, 

 a. b. c. 



Cardiaster cordiformis, Forbes, Ann. Nat. Hist. 2d series, vol. vi. 

 p. 443. 



On a recent visit to Ciply I had an opportunity of collecting the 

 Spatangus granulosus of Goldfuss in situ, and recognized in it 

 the same Echinite which has been noticed and figured by 

 Mr. Samuel Woodward, in his " Outline of the Geology of Norfolk,'"'' 

 under the name of Spatangus cordiformis. The flint casts from 

 the chalk of the north of Ireland, described by Colonel Portlock 

 imder the name of Holaster equalis, and now in the collections of 

 the Geological Survey, evidently belong to the same species. 



I constituted this genus for the species now represented and 

 described, and also for the curious Spatangus excentricus figured in 

 Woodward's work, above cited. Finding that there is a distinct 

 fasciole present in these urchins, and that this character is accom- 

 panied by peculiarities in the ambulacra, and, as far as I know, 

 invariably by the presence of a deep anteal sulcus with carinated 

 sides, I felt warranted in separating them generically from the 

 Holasters with which they had previously been associated. 



The Spatangus ananchytis of Leske, quoted by Lamarck with 

 doubt for his Ananchytes cor data, is evidently a Cardiaster in a 

 [iv. ix.] 4 K 



