81 



directed upward, so as to be wholly visible in n summit view, but can- 

 not be seen in a basal view. Plates plane and smooth. No ovarian 

 pores discovered, though our specimens arc in a tine stale of preser- 

 vation. 



Basal plates form a rounded expanding cup with a small concave 

 depression for the attachment of the coin mm First primary radials 

 large, as long as wide, three hexagonal, two heptagonal. Second 

 primary radials hexagonal, about as long as wide, and having the 

 appearance of the second primary radials in Actinocrinus. Third 

 primary radials smaller than the second, the twoadjoing the azygous 

 area hexagonal, the other three heptagonal, and in the ray opposite 

 the azygous area, bears, on each upper sloping side, two secondary 

 radials, which gives to this ray two arms. In each of the other rays, 

 the third primary radial supports, on each upper side, two secondary 

 radials, the last ones being axillary and bearing, on each upper 

 sloping side, a small tertiary radial, which gives to each of these rays 

 four arms or four small ambulacral openings to the vault. There 

 are, therefore, eighteen arms in this species. The arm formula is 

 4-1-244+4. 



In each regular interradial area, there are seven plates, one in the 

 first range, two in the second, two in the third and two in the fourth, 

 that separate the arms, and unite with the plates of the vault. The 

 azygous area is very large and contains eighteen plates. The first 

 one is in line with the first primary radials and of about the same 

 size. It is followed by three, in the second range, five in the third 

 range, five in the fourth range, and four in die fifth range, that con- 

 nect with the plates of the vault. One of the plates in the last range 

 appears as a small intercalated plate. 



The vault is rounded or subhemisphcrical and perfectly smooth. 

 There is a large plate at the summit which is surrounded by seven 

 somewhat smaller jnates, though unequal in size. These are sur- 

 rounded by two ranges of smaller plates and a few intercalated ones. 

 There is a small azygous orifice directed horizontally, at the lower 

 part of one of the plates, in the range of seven, that surrounds the 

 central plate. 



This is a very peculiar species, partaking of some of the characters 

 of Actinocrinus and some of the characters of Dorycrinus and is 

 referred to the latter, because its affinities seem to be stronger in 

 that direction, notwithstanding its smooth vault, than they are with 

 the former. We have two other specimens, which seem to agree 



