166 
OOLITIC URASTERIDiE. 
Stellaster Berthandi, Wriglit, n. sp. PI. XXI, fig. 2. 
Body pentagonal, sides with arclies much flattened ; tesserae thiclc and narrow, 
thirty-six to forty pairs around the marghi of one ray ; under surface of the disk covered 
with small, close-set, equal-sized ossicles ; ambulacral channels wide ; dorsal discal ossicles 
absent. 
Observation. — Since Mr. Sharp's specimen came into my hands for description a 
plaster-mould has been kindly communicated to me by Professor Berthand, of Macon, 
Saone-et-Loire, Prance. The original was collected from the ' Calcaire a Entroques,^ 
Macon. I mention it here, in connection with Stellaster Sharpii, Wr., as showing that 
Goniaster was a type of the Asteriadse which prevailed during the first stage of the 
Jurassic period, as the three forms we now know are all specifically distinct, and belong to 
the lower division of the Oolitic series. 
URASTER, Agassiz, 1835. 
Uraster spiniger, Wright, ii. sp. PI. XXI, fig. 1. Woodcut, fig. 41. 
Rays five, short, broad, curved, and petaloidal ; ambulacral areas wide ; margins 
bordered by a series of small ossicles, which form beaded ridges on each side of the 
ambulacral spaces. Ossicles support numerous small, short, blunt spines, which lie 
in profusion on the sides of the rays, and similar spines appear to have clothed the 
dorsal surface, and are seen "in situ" in the twisted portion of one of the rays, as 
depicted in the annexed figure. 
The disk small in proportion to the width of the rays and diameter of the Starfish. 
Dimensions. — Diameter of the disk one half inch ; length of each ray one inch ; 
breadth of a ray at its widest part four tenths of an inch. 
Description. — This Starfish was obtained from the Porest Marble, near Road, Wilts, 
where it was collected by Dr. H. P. Parsons. The specimen came into my hands in a 
very bad state, but by carefully backing it up with plaster of Paris I have been able to 
develop a considerable portion of its anatomy. The small ossicles which occupied the 
central portion of the ambulacral areas are absent, and there remains only the vacant 
spaces they at one time filled. The margins forming the boundaries of the areas are 
built up of a series of small ossicles, which are largest at the discal end, and diminish in 
size towards the termination of the rays. They form a beaded structure of considerable 
