FROM THE UPPER GREENSAND. 283 



the very excentral position of the ambulacral summit, which is situated behind the centre 

 of the upper surface (fig. 1). 



Locality and Stratigraphical Position. — This species is found in the Upper Green- 

 sand of Blackdown, Devon, where it is the only Urchin of frequent occurrence, and I 

 have no record of its discovery in any other Upper Greensand locality. 



Echinospatagus Collegnii, Sismonda, 1843. PI. LXIV, fig. 4. 



Toxaster Collegnii, Sismonda. Sugli Echini foss. del Contado di Nizza, 



p. 21, pi. i, figs. 9—11, 1843. 



— — Agassiz et Desor. Cat. raisonne des Echinides, p. 



132, 1847. 



— Brunneri, Merian. In Desor's Synopsis foss. Echinides, pi. xl, figs. 



2—4, p. 354, 1857. 

 Echinospatagus Collegnii, d'Orbigny. Pal. Francaise, Ter. Cretace, t. vi, p. 169, 



pi. lcccxlvi, 1853. 



— — Cotteau. Echinides des Pyrenees, p. 52, 1863. 



— — Cotteau. Echinides de l'Yonne, pi. lxiv, fig. 11, t. ii, 



1865. 



— — Ooster. Synop. Echin. Suisse, pi. xxv, fig. 8, 1865. 



— — De Loriol. Echin. Helv. Cretaces, t. ii, pi. xxx, 



figs. 1—5, p. 350, 1873. 



Diagnosis. — Test largely cordiform ; a little polygonal ; rounded, flattened, and slightly 

 depressed anteriorly ; contracted behind and obliquely truncated on the posterior border. 

 Upper surface convex, inflated at the posterior half, and much declined from the apical 

 disc to the anterior border. Highest point at the ridge behind the apical disc. Poste- 

 rior border quadrate, high, strongly and obliquely truncated. Base feebly convex in the 

 region of the plastron, and depressed near the mouth. Tue lateral parts of the ambitus 

 inflated. 



Dimensions. — Length 2 inches and 2 tenths ; breadth 2 inches and 1 tenth ; height 

 2 inches. 



Description. — This large fine Urchin was given to me several years ago by my late 

 lamented friend Dr. S. P. Woodward, with the remark that it was said to have been 

 collected from the Upper Greensand, Wiltshire, but the species was unknown to him, 

 so he begged me to figure and describe it when I came to the group. 



The test is large, cordate, and slightly polygonal, much elevated behind, and sloping 

 from the summit to the anterior border. 



The single ambulacrum is lodged in a large, wide, anteal sulcus, deeper above than 

 at the anterior border, which it depresses only feebly ; its poriferous zones are narrow ; 

 the pores are nearly equal in size, and set obliquely in pairs. 



