﻿288 Canadian Record of Science. 



Surface of the calyx marked by small, short, branching 

 grooves, which radiate from the centre and anastomose at 

 the margins of large plates of irregular shape. The exact 

 outlines of some of these plates are not clearly defined in 

 any of the three specimens that the writer has seen, 

 but two of the latter have part of the calyx crushed 

 in such a way as to shew parts of the margins of at least 

 two of the radials and of one of the basals. Judging by 

 these indications of the outlines of the plates and by 

 the peculiar sculpture of others, the composition of 

 the calyx would seem to be essentially as follows. In the 

 undivided and lower moiety of the divided portion there 

 appears to be a circlet of large, subpentagonal and 

 presumably basal plates, immediately above the column. 

 On the surface of these plates the branching grooves 

 radiate upward and outward, but not backward, and, 

 consequently, only the front and part of the lateral 

 margins of each of these plates is minutely sinuated. 

 Next to these supposed basal plates and alternating with 

 them there is a circlet of five large radials. These radials 

 are irregular in outline, but their margins are minutely 

 sinuated all round, except in the middle of the summit, 

 where each of these plates is overlapped by the distal 

 portion of the ambulacral area, as shewn in Fig. 3. On 

 each side of the anal region the upper and inner portions 

 of the margin of each of the two radials that partially 

 bound it, are slightly modified, as also shown by Fig. 3, 

 in which A represents the relative position of the middle 

 of the anal region. In the upper and lobate portion of 

 the calyx there appears to be a comparatively small and 

 presumably interradial plate, whose outline it is not yet 

 possible to define precisely, in or near the middle of each 

 of four of the lobes, the corresponding part of the fifth 

 lobe being occupied by the group of small plates which 

 surround and apparently cover the anus. 



The summit, or entire upper surface above the calyx, is 



