﻿266 SMITHSONIAN MISCELLANEOUS COLLECTIONS [VOL. 47 



top of the Siluric. In other words, between the Bohemian occur- 

 rence and the first American record there are the Lockport, Guelph, 

 Salina, and Bertie formations. No occurrence of this genus is 

 known in the highest Manlius and all of the Coeymans, but it reap- 

 pears in greatest abundance in the lower New Scotland in Ten- 

 nessee and Indian Territory. 



The geologic occurrence of these bodies — their gregarious habit, 

 with the great majority of the bulbs having their stalked end down- 

 ward — leads naturally to the conclusion that Lobolithus or Camaro- 

 c riii us, as found, represents nearly all of the animal, and that these 

 bulbs must be thecse either of cystids or crinoids. This was the view 

 set forth by the great paleontologist Barrande, and was also inde- 

 pendently reached by Ulrich and the writer. That Caniarocrinus is, 

 however, not a cystid theca nor crinoid calyx is clearly indicated by 

 the absence of ambulacra, mouth, and anus. Further, the axial 

 canal of the stalk does not pass directly into the medio-basal chamber ; 

 otherwise this cavity could be interpreted as the visceral cavity. On 

 the other hand, the insertion of the stalk into the root complex, all 

 of which divisions have a central canal, and the fact that the walls 

 of the camarse are nothing more than modified root-branches con- 

 necting with the second series of roots, seem to furnish conclusive 

 evidence that Caniarocrinus can be nothing more than the highly 

 specialized root of a crinoid. 



If this view apparently explains the true nature of Camarocrinus, 

 the question naturally arises, How can the vertical position of these 

 fossils in the strata be harmonized with the conclusion? The objec- 

 tion has been made that Caniarocrinus is too heavy for the float of a 

 crinoid, and while this appears to be true of the fossilized condition, 

 it does not apply to the living state. The writer has noted the weight 

 of the basal portion of a siliceous specimen of average size (estimated 

 to be y/ 2 inches in diameter, see plate xlh, figure 4), and cleaned of 

 all adhering calcareous matter by etching in hydrochloric acid. The 

 siliceous matter in such a specimen, it is estimated, will not exceed 

 4 ounces — a weight certainly not too great for a float of this size. 1 



1 This paragraph was shown to a critical friend and he holds that the de- 

 ductions as stated are in error for the following reasons: (1) A siliceous 

 pseudomorph, after it has been etched, is lighter than the original calcareous 

 structure, because the acid honeycombs the walls and also because siliceous 

 pseudomorphs are often mere skeletons of the outer and inner sides of the 

 walls, leaving the greater central space free of material. Answer: In tlie 

 specimen selected for ascertaining its original weight, the walls are nearly 

 solid, though there is some honeycombing due to etching. Further, the frag- 

 ment weighed is the basal portion, therefore the heaviest part of the bulb. 



