New Orders and New Families in the Class Echinodermata. 223 



central aperture, if one exists, has not been discovered, and the 

 structure of the terminal end of the anomalous coil is wholly un- 

 known. The internal radiating S3*stem of pores ma} T be compared 

 with that of the family Cyclocj'stoididye, and here the analog}" in 

 structure, with other families in the class Echinodermata, so far as 

 known, ceases. The terminal end of the coil being unknown has led to 

 the suggestion of the possibility of its having been connected with the 

 vault of a crinoid, but as no genus is known having any such append- 

 age, and some classification seeming desirable, this family has been 

 proposed. 



Familv Cyclocystoidid^e, n. fpm. 



This family is founded upon the single genus Cyclocj-stoides, and 

 defined as follows r 



Body free, consisting of«a circular disk, and having a margin com- 

 posed of a series of perforated plates. Within this marginal series the 

 disk is covered with an integument of small plates, except, possibly, a 

 small central aperture. The rim or marginal series contains a tubular 

 channel, making the complete circle, which is connected with the in- 

 terior, by numerous pores, that radiate from the center, and repeatedly 

 bifurcate before reaching it. The inner side of the rim is grooved, 

 for the reception of the internal part of the disk, and the outer side 

 depressed and scarred, either by mammillary elevations or concave 

 depressions, as if for the attachment of ossicular or other processes. 

 The tubular channel is connected with the exterior by minute circular 

 pores, which were probably analagous, in their purpose, to the calycine 

 pores in the Cystideoe. 



HOLOCYSTITES JOL1ETENSIS, D. Sp. 

 [Plate IX., figs. 1 and la, natural size.] 



The body is rather above the medium size, and almost completely 

 obovate in outline. It is covered by numerous irregularly disposed 

 convex plates, differing much in size and form, and not susceptible of 

 being thrown into circular ranges, as is usual in this genus. 



The species is founded upon casts, but these preserve the form of 

 the convexity of the plates, and one of them, as shown in fig. 1, pre- 

 serves the cast of some of the pores with which the plates were perfor- 

 ated, which draw this species in near relationship with H. pustulosu.s. 

 described in vol. 1, p. 13-1, pi. 6, figs. 1 and la, of this Journal. Both 

 species were covered with irregular, convex, pustulous, porous plates, 



