17 
Contributions to the Paleontology of Gloucestershire :—A descrip- 
tion, with Figures, of some new Species of Echinodermata from 
the Lnas and Oolites. By THomas Wricut, M.D. &c., Pro- 
at the Natural Sciences in the Cheltenham Grammar 
chool. 
Reap 47TH May 1852. 
Cidaris Edwardsu, Wright. PI. I. fig. 1, af. 
Test crushed, the form therefore unknown. Ambulacral areas 
narrow, with two rows of small perforated tubercles, and 
smaller perforated ones interspersed amongst them ; interam- 
bulacral areas about four times the width of the ambulacral, 
having two rows of large tubereles with confluent areolas ; the 
primary spines long, with a compound structure; the secondary 
spines short with blunt apices, the surfaces of both sculptured 
with delicate longitudinal lines ; mouth armed with powerful 
jaws, each with three prominent tricarinated ridges. Upper 
part of the test and ovarial disc unknown. 
Deseription.—It is much to be regretted that no other speci- 
men of this noble Urchin but the one before us has been ob- 
tained from the Lias of Gloucestershire, and as the specimen 
exhibits only the lower half of the test, many points of its ana- 
tomy remain unknown; enough of its structure, however, is 
shown to enable us to point out some important affinities and 
differences in this rare species. 
The narrow ambulacral areas are provided with two rows of 
small perforated tubercles, amongst which smaller tubercles are 
irregularly scattered; these tubercles all support short stout 
spines with a minutely sculptured surface, and which are abun- 
dantly preserved in situ on the specimen. The wide poriferous 
avenues are occupied with large oblong pedal pores with very 
thin partition-walls between them, a circumstance which forms 
a good diagnostic character between C. Edwardsii and C. Fowleri, 
which it very much resembles in many points of structure, the 
pores in C. Fowleri being small and separated by thick partition- 
walls. The interambulacral areas are four times the width of 
the ambulacral, and are occupied by two rows of large tubercles 
set closely together in a vertical direction, so that the areolas 
above and below are quite confluent throughout. 
VOL. Il. ie c 
