PLATE I. 



Arachnocrinus extensus Wachsmuth and Springer. 



Onondaga (Upper Helderberg). Middle Devonian. 



Fig. 1. The type specimen, from tlie Falls of the Ohio River at Louisville, Ky.; with 

 calyx crushed, hut showing the ponderous, multihrachiate arms, and the unequal 

 distribution of I Br, the anterior ray bifurcating nnuh higher than the others; 

 the dorsal canal and small \eiitral grooves are shown on the cross section of 

 brachials at several places. The specimen apparently has (i rays. 



2. Ventral side of another specimen from same locality, showing anal opening through 



dorsal cup below RR. 



3. Stem ossicle found in same beds and locality, undoubtedly belonging to this species. 



X 2. 



4. Specimen from near LeRoy, Livingston Co., N. Y., probably of this species, dorsal 



view; arms much displaced, and basal plates partly broken away. 



Arachnocrinus knappi Wachsmuth and Springer. 



Hamilton Group, Beargra.ss Creek, Louisville, Ky. 



Fig. .5. The type specimen, posterior view, showing large anal opening between post. 

 B and RR; and the arms to the first bifurcation on the 10th to 14th brachial. 



6. Left post, interradial view of same specimen. 



7. Basal view of same, showing margin of undivided IBB, the median part being 



destroyed. 



Gasterocoma antiqua Goldfuss. 



Middle Devonian. Eifel, Germany. 



Fig. 8. Post, view of calyx, showing anal opening, for comparison with fig. 5. Copy from 

 Schultze, Echin. Eifel, XH, fig. 16. 



