282 TWENTIETH REPORT ON THE 8IATE CABINET. 



XIV. NOTE ON THE GENUS PALilASTER, 



WITH DESCRIPTIONS OF SOME NEW SPECIES, AND OBSERVATIONS UPON 

 THOSE PREVIOUSLY DESCRIBED. 



»»#«# 



GENUS PAL^ASTER (Hall). 



In the second volume of the Palaeontology of New-York, page 247,* I 

 proposed the name Pal^aster, to include a species from the Niagara 

 group and one from the Hamilton group. I have subsequently referred to the 

 same genus a species from the Trenton limestone, which I previously pub- 

 lished under the name of Asterias matutina. The original specimen described 

 under this name was in such a condition that the ambulacral and adjacent 

 plates could not be distinctly recognized, and the upper side remained 

 imbedded in stone. The generic description is therefore very meagre, and 

 the figure was intended to illustrate all that could be seen. 



The species is thus described : "Body stellate; disc small; arms short, 

 •* terete with a deep avenue on the lower side, which is margined by short 

 ** strong spines ; centre of plates (in the fossil) nearly smooth, margins 

 ** strongly granulate ; lower side of the arms showing two ranges of plates 

 ** on each side of the avenue ; the outer range composed of short hexago- 

 ** nal plates, with an inner range of smaller ones alternating, the latter 

 ** usually covered by tufts of spines ; a large pentagonal plate inserted at 

 ** the base of the arms, on the lower side." 



I have distinctly recognized the two ranges, marginal and adambulacral 



not shown in the figure as they should have 

 at the axil of the ray ( though the adjacent 

 small oral plates of the inner range are not seen) is evidently part of an 

 incomplete series, and clearly belongs to the marginal range. 



In 1856,t Mr. Salter adopted the name Pal^aster for fossil star- 

 fishes without disc and having deep avenues, etc. 



• This volume was printed in 1850, but was published in 1852. 

 t Proceedings of British Association, August 1856. 



2 [Originally published December 1866.] 



plates ; but the inner ones are 

 Ibeen, while the large plate at 



