210 PALJEONTOLOGY O? NEW-YOBK. 



Fig. 3 b. Lateral view of the preceding specimen, which is broken off near the base of the 

 arms. 



Fig. 3 c. View from below, showing a portion of the cavity ; the sides arching over, and con- 

 tracting to the angular canal which extends to the summit. The interior of this 

 cavity is formed by the expansion of the solid ribs between the fingers, which 

 unite, lining the entire upper part of the cavity ; beyond which, their inner edges, 

 uniting just before reaching the centre, produce the angular canal which reaches 

 from the cavity to the summit. By this union of the interior edges of these ribs, it 

 will be perceived that the tentacula are confined within solid walls, and become (as 

 before remarked) anchylosed, forming, with the ribs, essentially a solid mass pene- 

 trated only by the narrow canal. 



It should be observed that this specimen is somewhat compressed, and in conse- 

 quence'the form of the canal is distorted. 



Fio-. 3 d. Another specimen, showing a longitudinal section of the upper part, and a portion of 

 the cavity below. The centre is marked by the angular canal formed by the junction 

 of the ribs, as just described. On the outer margins are the joints of the fingers, 

 with the tentacula attached, all converging inward and upward to the walls of the 

 central canal. 



This specimen, with the preceding, when taken in connexion with the other figures 

 where the base is preserved, give a very clear idea of the structure of this peculiar 

 crinoid. 



Position and locality. In the shale of the Niagara group at Lockport, Rochester and Mar- 

 shall's mill in Sweden, Monroe county, New-York ; and in several localities in Kentucky and 



Tennessee. {State Collection.) 



597. 2. EUCALYPTOCRINUS CtELATUS. 



Pl. XL VII. Fig. 4 a- e. 

 Hypanthocrinites calatus. Hall, Geol. Rep. 4th Dist. N. York, 1843, pag. 113, fig. 1. 



This species was separated from the preceding, on account of the sculptured surface of the 

 hand and finger-joints, as well as the surface of the interstitial ribs. The plates below are also 

 much more strongly tuberculated than any other specimen observed. This character is the 

 principal external one, by which it differs from the specimens before described. In measuring 

 the extension of the finger-joints towards the centre, they are found to be proportionally much 

 longer than in either of the specimens fig. 2 d and Bd, which furnishes an additional character 

 on which to found a separation. For these reasons, I have allowed the species to remain as 

 published, imtil an opportunity offers for a comparison with other specimens. 



Fig. 4 a. The specimen, somewhat broken in the upper part. 

 Fig. 4 b. The surface of one of the interstitial ribs, enlarged. 



Fig. 4 c. Several joints of the fingers enlarged and separated, showing their deep interlocking 

 with each other near the base, and the character of their surface marking. 



