FROM THE GREAT OOLITE. 339 



there arc from twenty to thirty, disposed in three or four rows (fig. 2d); and those 

 at the base are somewhat larger than the tubercles on the upper surface. The apical disc is 

 small, and nearly central ; its elements are so intimately soldered together, that its general 

 form alone can be made out ; none of the specimens I have examined display the separate 

 plates ; the eyeholes are marginal, at the apices of the ambulacra, and the ovarial holes 

 are further outwards, and between them, whilst the madreporiform tubercle occupies the 

 centre of the disc. The test is very thin, and almost always deformed by tumidity, and 

 the upper surface is often irregular from this cause. The beauty and regularity of the 

 small specimen I have figured, forms an exception to almost all the other specimens 

 I have seen. 



Affijiities and differences. — This species resembles most E. orbicularis, Phil., which is the 

 only form amongst its Oolitic congeners for which it can be mistaken. The following diag- 

 nostic characters will enable the geologist to distinguish these allied forms from each other. 

 In E. JFoodtoardii the sides are very tumid, and the dorsal surface is flat, whilst in E. orbicu- 

 laris the sides taper, and the upper surface is convex. In E. IFoodwardii the base is flat, and 

 the inter-ambulacra are vslightly produced, whilst in E. orbicularis the base is concave, and 

 the inter-ambulacra convex and prominent. In E. Woodwardii the anal valley is 

 narrow, in E. orbicularis it is wide. In E. Woodwardii the outline is sub-quadrate, in 

 E. orbicularis it is circular; the petaloidal disposition of the dorsal portion of the 

 poriferous zones extends farther down the sides in E. orbicularis than in E. Woodwardii. 

 It difiers from E. Brodiei and E. scutatus in the anal valley extending from the disc 

 to the border, whereas in these species there is always an undepressed portion of test 

 between the disc and the valley. Between E. Woodwardii and E. clunicularis the dif- 

 ference in the general shape and development of the posterior lobes is so great, that they 

 cannot be mistaken for each other. 



Locality and Stratigraphical position. — I have collected this urchin from the Great 

 Oolite at ]\Iinchinhampton, near Cirencester, at Salperton tunnel, Great Western Railway, 

 at Highgate, and near Pewsdown, Gloucestershire, and at Burford, Oxon ; as far as I 

 know, it has not been found out of the Great Oolite. Mr. John Bravender, of Ciren- 

 cester, collected this species at Tetbury, and between Tetbury and Bourton-on-the-Water, 

 embracing a distance of twenty-five miles, in ten or twelve different localities ; the 

 specimens were found in a hard marly rock, at the upper part of the Great Oolite ; the test 

 is unfortunately not often well preserved. Mr. Frederick Bravender has kindly sent me 

 the following note on the distribution of this urchin, which I herewith give entii'e : 



" EcJdnobrissus Woodwardii is generally found in a rubbly bed, nearly, if not quite, at 

 the top of the Great Oolite ; and although this stratum covers a considerable tract of elevated 

 country in the neighbourhood of Cirencester, this urchin has not been collected very 

 plentifully, except in one or two localities. It has been found at Perrimore Quarry, on 



