J 



54 



loaned it to me for description. Its large size and the preservation in 



it of portions not well shewn in the type specimen make it of special 



value. Comparison with the type specimen and with a small specimen 



collected by the author at Division Streee, lea Is me to believe that the 



specimen liguied belongs to this species. 



The si)ecimen lies on a slab with the popteiior side upward, show- 



inf^ a y.ortioa of the column, the posterior side of the cup, two arms 



aud the ventral tube. Three pentagonal under basals are visible, also 



the heptagonal posterior basal, hexagonal left posterior basal, a 



part of the right postericr basal, the radials and arm-plates of two 



arms, and the ventral tube. The posterior basal is heptagonal and the 



right and left posterior basals hexagonal. The right posterior radial is 



compound, consisting of a pentagonal and a hexagonal plate, and followed 



by seven tetragonal and one axillary brachials. The left posterior 



radial is ])entagonal and followed by five tetragonal and one axillary 



brachials. Of the secondary series three consecutive tetragonal pieces 

 is the lai'gest number preserved in either ray. 



The anal plate, which rests on the truncated posteiior basal is 

 heptagonal, abutting by two sides on the right posterior radial and by 

 one on the left posterior radial. Of the three remaining upper sides 

 two cany two adjoining series of the larg3 bottom plates of the ventral 

 tube and the third, which is short, .supports one side of the bottom plate 

 of an adjoining series. The plates ot the two rows of the ventral tube , 

 which are supported by the anal plate are hexagonal, resting on each 

 other by their longest side and altei'natiug with those of the adjoining 

 rows. The pieces are about as wide as high at the base of tlie tube, but 

 as they rise they become shallower, while retaining their width, until at 

 the sixth plate the height is one-third the width, whence they reduce 

 regularly until one inch from the anal plate, where the upper part is 

 unfortunately broken off. The upper plates of this specimen show the 

 commencement of the sculpture and its transition towards the pattern 

 shown in that part of the tube whish in the type specimen is intact. 

 The row of ventral tube plates to the right of those described is similar 

 to them, but rests on the second plate of the compound radial and abuts 

 on the first brachial. Another row further to the right and which rests 

 oil the first brachial is composed of smaller plates. The lower portion 

 of the ventral tubes is thus seen to be articulated with the right posterior 

 ray as high as the top of the first l)rachial. 



_ The cuknrni is (i\iiuquei)aititc witii sutures radially situated : the 

 periphery of the section is stellate with the sutures in the re-entering 

 angles ; and the canal is pentagonal wih the angles on the lines of the 

 sutures. 



