182 



D. Echinoderinata. 



They Lave horseshoe-shaped rims, the arches of which are directed upwards, 

 while the two ends slant downwards and outwards. Radials separated from the 

 centrodorsal by a complete circle of basals. The first 6 or more brachials bear 

 no pinnules. Carpenter ( 15 ) ; hierher balanoides P. H. Carp., cubensis Pourt. sp. 

 und Wyrillin. sp. von der Challenger-Expedition. 



Cy clocy stoididae n. fam. Body free, consisting of a circular disk, and hav- 

 ing a margin composed 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 chan- 

 nel, making the complete circle, which is connected with the interior, 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 analogous in their purpose to the calycine pores in the Cysti- 

 deae. Miller ( 58 j ; hierher Cydocystoides. 



Gymnocrmus n. gen. Gestielter Crinoide mit sehr unregelmaCiger Kelcherhohung, 

 auf deren Rand ein axillares Radiale, fest verschniolzen , sich erhebt und 2 Arti- 

 culationsfacetteu erkennen laGt. Danach wiirde G. nur 2 Arme besessen habeu. 

 Loriol nach Dames ( 25a ) ; Letzterer vermuthet, es handle sich nur urn eine De- 

 formitat; hierher Moeschi n. sp. 



Lichenoerinoidea u. ordo et n. fam. The body attached during part or all of 

 its life to foreign objects. It is circular, convex upon the upper side and more 

 or less crateriform surrounding the central-stalk-like appendage. The lower side 

 at some period of life possessed a thin attaching plate. The upper side is covered 

 with numerous polygonal plates, without any evidence of the presence of ambu- 

 lacra, arms, mouth, pectinated rhombs or pores connecting the exterior with the 

 internal cavity. The inferior of the visceral cavity contains numerous radiating 

 upright lamellae, that support the polygonal plates of the upper side and often 

 leave their impression like the radiations of a star upon the object to which it 

 was attached. The stalk rises from the central depressed area and consists, at 

 first, of interloking plates, but afterwards, of circular ones, like those of a crinoid 

 column, and finally tapers to a point. It was flexible and perforated with a lon- 

 gitudinal channel, though the perforation has not been satisfactorily ascertained 

 at the upper terminating point. Miller ( 58 j ; hierher nur Lichenocrinus. 



Myelodactyloidea n. ordo. Body free, discoidal, and possessed of an internal 

 radiating system of pores, which increase, by division, from the center to a 

 tubular channel in the circular margin or surrounding coil. Miller ( 5S ) ; hierher 

 die Cy clocy stoididae und Myelodactylidae. 



Myelodactylidae n. fam. Body free, discoidal, and resembling a coil rolled 

 in the same plane, and covered upon either side by finger-like processes from 

 each succeeding turn overlapping the next inner one. The whorls are composed 

 of a series of plates, having a tubular channel within, and perforated and finger- 

 like processes upon the exterior, directed toward the center, and flattened down 

 upon the next inner whorl to which they are attached, and form a porous con- 

 nection from the tubular channel of one whorl to the next inner one. The cast of 

 the pores of the inner whorl resembles the radiating spokes of a wheel : they are 

 multiplied in connecting the tubular channels of each succeeding whorl, thus mak- 

 ing the internal radiating system doubly complicated. The central aperture, if 

 one exists, has not been discovered, and the structure of the terminal end of the 

 anomalous coil is wholly unknown. The internal radiating system of pores may 



