29 



primary radials, about the same length as the secoud, expand to 

 the lateral angles, and bear upon each upper sloping side, except 

 one, a single secondary radial. Upon one side of the radial series 

 opposite the azygous side there are three secondary radials, the 

 last one of which bears a cuneiform arm plate. The first second- 

 ary radials are large and bear upou each upper sloping side two 

 tertiary radials. There are, therefore, four arms to each of four 

 radial series and three arn:s in the radial series opposite the azy- 

 gous area, making nineteen arms in this species. The arm bases 

 are not large and the arms appear to be composed of a single 

 series of cuneiform plates. 



The first interradials are the larger plates of the body and have 

 nine sides, in three of the areas; but, in the other two areas, there 

 are two interradial plates in the first range and together they are 

 much larger than the single first interradials. The two interradials 

 in the first range in the two areas may be seen to abut upon the 

 two large first primary radials in Figure 10, one plate extending 

 below the other and one of them may be seen on the left of Fig- 

 ure 11. We cannot say that the two large first primary radials, 

 followed laterally by two plates, in the first range of interradials, 

 represent an abnormal development. We have only one specimen. 

 The two first primary radials are substantially alike and the two 

 peculiar interradial areas are substantially alike. If they are ab- 

 normal there is regularity about them, and they are each separated 

 by a four-armed radial series from the three-armed series. There 

 is only one plate in the second range, in three of the areas, and 

 two in the other two areas. In the third range there are three 

 plates, the central one is the larger and unites with two plates on 

 the vault and the lateral ones form part of the arm bases. There 

 are no iutersecondary radials. There is an azygous side if we 

 would embrace within it two radial series and three interradial 

 areas, but there cannot be said to be a single azygous area as that 

 term is applied in the description of crinoids. 



The vault is only slightly convex but I'ather strongly depressed 

 in the interradial areas between the arm bases. There is a small 

 subcentral proboscis. The vault is covered with rather large 

 polygonal plates, the two, in the interradial areas that abut upon 

 the plates in the third range of the interradials, are elongated and 

 the larger plates of the vault. All the plates bear tubercles and 



