New PdloBozoic Starfish* 69 



species there is a row of tubercles along the dorsal furrows, and a 

 very strong one at each end of the neck segment, and, besides, 

 the P'labella is more narroweu towards the front than it is in our 

 species. 



The surface appears to be smooth. 



Locality and Formation. — Anticosti, Hudson River group. 



Collector. — J. Richardson. 



ARTICLE VII. — Description 0/ a new Palaeozoic Starfish 

 of ths genus Paljeaster, from JSFova Scotia. By E. 



BiLLIKGS. 



Pal^easter parviusculus. N. s. 



Description. — The specimen is about six lines in diameter* 

 The ravs are two lines in lentjth and one line and a half in width 

 at the base, tapering at an angle of a little less than 45°. The 

 five oral plates are sub-pentagonal about half a line in width. 

 The first adambulacral plates of each pair of adjacent rays are in 

 contact with each other outside of the oral plates, and not com- 

 pletely separated as they are in P. Niagarensis, There are six 

 or seven adambulacral plates on each side of the ambulacral 

 groove in each ray, and they gradually decrease in size from the 

 oral plate outwards to the point of the ray. The width of the 

 ambulacral groove is equal to one-third the width of the ray and 

 consequently the adambulacral rows of plates are also each equal 

 to one-third the whole width of the rav. In each groove there 

 are two rows of small and apparently nearly square ambulacral 

 plates, twelve or fourteen in each row, and they seem to be con- 

 tinued round on the inner margin of the oral plates ; the mouth 

 is about one line wide. 



This species differs from P. Niagarensis, (Hall), (Pal. N. Y., 

 Vol. 2, page 24Y, pi. 51, figs. 21, 22, 23,) in being smaller, the 

 rays not so slender, and more importantly in the junction of the 

 adambulacral plates outside of the oral plates. 



In the 3rd Decade of the Geological Survey I have defined the 

 genus Stenaster as difi'ering from Paheaster, by the possession of 



