30 



* 



The other FINGER JOINTS (PL. vi. fig. 19. to 27.) assume more of a horse- 

 shoe shape, are traversed by a canal, and with regard to their superior surfaces 

 are of two distinct formations. Those of the FIRST FORMATION (PL. vi. fig. 18. 

 and 24.) have on the inferior and superior surfaces, a ridge placed in an oblique 

 direction, so that that on the inferior, crosses that on the superior surface. 

 The finger joints of the SECOND FORMATION (PL. vi. fig. 19. to2'i.) have on 

 one side the oblique transverse ridge, (fig. 24.) and on the other, two slender 

 ridges crossing each other at right angles, and sending off throughout the 

 exterior space to the circumference, from one to five less conspicuous radii (fig. 

 19. to 23.) The joints of the first and second formation are so arranged over each 

 other when forming the fiuger, (PL. vi. fig. 25.) that the radiated surfaces of two 

 joints of the second formation always adhere together, supporting one of the first, 

 en which again two of the second formation rest. 



Although I have not a specimen showing the tentaculated fingers in an 

 entire state, yet from the general simple construction of the APIOCKINIIES 

 ROTUNUUS, and the non-occurrence of the cuneiform dividing joints in the 

 strata which afford these specimens, I conclude that the tentaculated fingers 

 were simple, and the animal had no more than two. 



From the above observations we may be able to obtain a tolerably accurate 

 idea of the general form, appearance, and organization of this animal in its 

 original and perfect state, and form a restoration of the whole in the same 

 manner that the antiquary proceeds to restore a ruined temple. 



We shall then (PL. i. fig. 1.) consider it as attached by its conical base to 

 some marine body at the bottom of a former ocean, whence arose its short and 

 slightly flexible column, terminated at the upper part by the swelling pyrifonu 

 body which contained its viscera and rnouth surrounded by ten fingers, each 

 fringed by numerous tentacula, either expanded like an opening flower when 

 the animal was in search of its prey, or contracted and closed when in a state 

 of repose. 



If we next examine the interior funnel-shaped cavity (?L. in. fig. 1.) we 

 may trace two rows of orifices opening laterally, each row exhibiting five. 

 The inferior orifices open between the first and second costal joint (PL. IT. 

 fig. 14. and 15); the superior orifices open between the junction of the sca- 

 pula and the two incumbent arm joints (Pi., v. fig. 4.) Below the subpen- 



