20 Dr. T. Wright on new Species of Echinodermata 



disposed in a single tile. The intcrambulacral areas are about 

 five times the width of the ambulacral, and have two rows of 

 primary tubercles of moderate size, with from five to six in each 

 row. The mammillary eminences on which the tubercles are 

 supported are surrounded by areolas deeply excavated out of the 

 substance of the test plates ; the margin bounding the areolas is 

 raised into a ridge on which a distinct row of close-set granules is 

 disposed, so that each tubercle is thereby separated from its fellow; 

 the elevation of the marginal ridges produces a zigzag depression 

 down the centre of the areas, which is covered with a small 

 close-set granulation. The mouth-opening is small and circular, 

 and lies in a slight depression ; the apical disc is absent in all 

 the specimens that have yet been found. The crenulations on 

 the mammae are small, but distinct, and the tubercles are of 

 moderate size and not deeply perforated. 



Affinities and differences. This Urchin has many affinities with 

 C. coronata, Goldf., and C.propinqua, Miinst., and has been cata- 

 logued as the former by some authors ; it is therefore important 

 that we should point out the diagnostic characters by which it is 

 distinguished from them. In both these corallian forms the am- 

 bulacral areas have four rows of granules, whilst in C. Bouchardii 

 there are only two rows. From C. propinqua and C. coronata 

 it is further distinguished by having more rows of primary 

 tubercles in the interambulacral areas, in having the areolas 

 smaller and more deeply sunk, the tubercles proportionately 

 smaller, and the marginal circle of granules smaller and set 

 closer together. With C. marginata, Goldf., it has some affinity 

 in the excavated style of its areolar spaces, but it is distinguished 

 from this beautiful form in having the tubercles smaller and 

 more numerous. In C. marginata the ambulacral areas moreover 

 are broader and more prominent, and they support four rows of 

 small granules, whilst in C. Bouchardii there are only two. With 

 C. elegans, Goldf., it has no resemblancewhatever; it belongs there- 

 fore to a different group of Cidarites than these foreign corallian 

 forms. From C. Fowleri, nobis, it is distinguished by having 

 narrower and more deeply concealed poriferous avenues, fewer 

 primary tubercles in the interambulacral areas, and deeper exca- 

 vated areolar spaces with a more elevated marginal rim around 

 them : these characters serve to distinguish C. Fowleri from 

 C. Bouchardii at a glance, and the same diagnostic traits separate 

 it from C. Edwardsii, nobis. 



Locality and stratigraphical range. We have found this spe- 

 cies in the Pea-grit of the Inferior Oolite of Crickley, Leck- 

 hampton, and Birdlip Hills, Gloucestershire, but have never met 

 with any traces of it in the Upper Ragstone beds so rich in 

 Urchin forms. Some separate plates collected from the Bradford 



