490 s. goto: 



stone hard, the actinal side is concave in the disk and plane in 

 tlie arms ; tlie disk is comparatively large and elevated in the 

 form of an irregular turret on the abactinal side ; the arms are 

 relatively slender, triangular in cross section and have up-turned 

 tips ; the interbrachial arcs are quite open and well-rounded (PL 

 XIV, fig. 221, 222). 



Siijycromarfj inah. ^There are 23 superomarginal plates, which 

 are of a triangular shape on the sides of the arms, irregularly 

 roundish or polygonal in the interradial arcs, and nearly rectan- 

 gular close to the tip of the arms. They form the lateral margin 

 of the arms, and show comparatively little on the actinal side. 

 The individual plates are comparatively small and are completely 

 covered over with flattened polygonal granules. In most of the 

 interradii there are a few intercalary plates between the inferior 

 and superior marginal series. The superomarginals are entirely 

 destitute of pedicellarise in my specimen. This is a difference of 

 some importance from the descriptions of previous authors, but 

 I believe this character is subject to a great deal of variation. 



Inferomarginals. — The inferomarginals are coincident with the 

 superomarginals, and are entirely confined to the actinal side. 

 The individual plates are nearly elliptical in the interbrachial arcs 

 and at the base of the arms, but they present a straight border 

 against the superomarginals along the remainder of the arms. 

 They are completely covered over with granules exactly similar 

 to tliose of the superomarginals, and are like them entirely desti- 

 tute of pedicellariœ. 



Adambulacral plates. — The adambulacral plates are compara- 

 tively long and narrow, and bear two series of spines, which stand 

 out erect in the dried specimen. There are 7-8 spines in the 



