462 



REMARKS ON NEW SPECIES OF CRINOIDEA, 



less perfect specimens than that figured, exhibit the basal pit close and less deep than I). 

 lacus and several others ; the sides rising nearly perpendicularly with the base of the body. 

 The "atlas" is seen in the figure (n, PI. XXVII), surrounded by the false basals, which 

 form the outer ring within the basal pit. The basals, as is usual in examples of this 

 genus, are hidden by the first radials. 



Inter 'radial fields. — These are five in number. The pieces composing the several fields 

 vary in number, from seven to nine to each field. The first is large, subovoid ; nine-sided ; 

 a little larger than any other pieces of the calyx. Upon the upper margin of these rest 

 another large piece, equal in size to the radial pieces ; they differ in form, but are all six- 

 sided. Upon the upper margins of these rest three interradials of the third series, except 

 in one field, where there arc only two of these pieces, the third side supporting one of the 

 superradials. The fourth series consists of two to each field, except one, which has four 

 pieces in the fourth range of the intcrradial field. The fourth range supports two pieces 

 to each field ; the upper end of these are joined to the points of the long pieces which lie 

 between the lobes on the dome. 



Interbrachiah. — From two to four to a field, and are wedged between the arm-bases ; 

 when of four pieces, they are in pairs, one above the other. The dome is covered by large 

 pieces ; each field between the lobes contain a pair of the largest, which reach from the 

 arm-bases toward the proboscis; they are six or seven- sided ; long; broadest at the upper 

 extremity ; pointed, or very slightly truncated at the lower end ; joining each other by 

 their longest sides, at the centre of the depression between the lobes. A circle of large 

 pieces surround the dome ; all of these rest partly upon the ten long pieces. The pieces 

 composing this zone are of different sizes ; they also differ in form ; all six-sided; two of 

 the largest pieces of the circle rest directly over two of the long pieces ; three other groups 

 of the long pieces unite under the suture, uniting two of the pieces forming the circle, 

 so that the sutures uniting both sets of pieces, form one line from the arm-bases to the 

 base of the second circle surrounding the dome near the base of the proboscis. The speci- 

 men figured has the proboscis broken off' through the pieces of the second zone which 

 surround it. Below the zone described, and between the groups of long pieces, are groups 

 of from five to seven pieces, the upper one of which is joined to the circle above the group 

 of long pieces, and on which it rests. The lowest piece of these groups is lanceolate ; is 

 lodged between the arm-bases, and unites with the intcrbrachials. The upper and largest 

 piece of these several groups is of the same size and form as the pieces comprising the first 

 zone around the top of the dome. Around the arm-bases, the pieces are numerous and 

 quite small. The pieces comprising the lower zone, and the large ones of the groups 

 above the arms, are surmounted by a group of from three to five rough, pointed spines, 

 confluent near their bases. The fragments of the second zone, remaining at the base of 



