238 



ACROSALENIA. 



careful collector, separates the Cornbrash from the Forest Marble. The beauty of these 

 specimens, and the admirable state of preservation in which they are found, forms one of 

 the marvels of the Oolitic fauna ; a great quantity of fine tests are collected from the gray 

 brashy beds of the Cornbrash near Chippenham. Mr. Bristow obtained it from the Corn- 

 brash near Wincanton ; Mr. Pratt from the Forest Marble at Hinton Abbey ; Mr. Hull 

 found very large specimens in a cream-coloured, calcareous, semi-indurated, marly bed of 

 the Great Oolite near Burford, in a quarry not far from the Bird-in-hand Inn. I dis- 

 covered two specimens in the Great Oolite limestone of Minchinhampton Common. The 

 specimens said to have been found in the Inferior Oolite have been ascertained to be 

 A. Lycettii. The Rev. A. W. Griesbach collected quinquefid spines of this urchin in the 

 Great Oolite at Wollaston, Northamptonshire, along with Acrosalenia pustulata. This 

 species, therefore, belongs to the Bathonian stage, and is a very characteristic urchin of 

 this great zone of life. 



Acrosalenia spinosa, Agassiz. PI. XVII, fig. 3 a, 5, c, d, e,f. 



Acrosalenia spinosa. Agassiz, Catalogus systematicus Ectyporum Echinoderrnatum 

 fossilium, p. 9, 1840. 



— l^vis. Agassiz, Catalogus systematicus Ectyporum Echinodermatum 



fossilium, p. 9, 1840. 



— spinosa. Agassiz, Echinodermes Fossiles de la Suisse, ii, tab. 18, figs. 1 — 5, 



J p. 39. 



— — Cotteau, Etudes sur les Ecliinides Fossiles, pi. 3, figs. 6 — 11, 



p. 58. 



— — Agassiz et Desor, Catalogue raisonne, Annales des Sciences 



Naturelles, 3 me serie, tome vi, p. 343. 



— — Forbes, in Morris's Catalogue of British. Fossils, p. 70. 



— — Wright, Annals and Magazine of Natural History, 2d series, vol. 



viii, pi. 12, fig. 3, p. 265. 



— — Bronn, Lethaea Geognostica, dritte Auflage, Band ii, tabl. xvii, 



fig. 7, p. 144. 



— — Desor, Synopsis des Ecliinides Fossiles, tabl. 20, figs. 14 — 16. 



— — D'Orbigny, Prodrome de Paleontologie, tome i, ll me £tage, Batho- 



nien, p. 320, No. 417. 



— radiata. Forbes, Memoirs of the Geological Survey, IV Decade. Note on 



new species of British Acrosalenias. 



Test sub-pentagonal, depressed ; ambulacra straight, prominent, with two marginal rows 

 of small spaced-out tubercles ten to twelve in each row ; inter-ambulacra with eight to nine 

 primary tubercles in each row, large at the circumference, gradually diminishing towards the 

 peristome, suddenly so on the upper surface ; miliary zone narrow at the circumference, wide 

 and naked in the middle at the upper surface ; apical disc large, sur-anal plate single ; 



