THE AMERICAN MUSEUM JOURNAL 



the lower side in a fine matrix whicli preserved them like a mould. 

 The other individuals of the colony settled down on top of these 

 and, not having a soft or plastic bed to receive and preserve 

 them, were crushed out of shape and disarticulated, and their 

 component plates were indiscriminately mixed up. The whole 

 mass was cemented together under pressure, forming a slab, — a 

 thin layer of limestone as we now find it, — with the Crinoid 

 bodies preserved only on its lower side. The largest of these 

 lenticular layers of limestone was about fifty feet long and twenty 

 feet wide with a thickness of half an inch in the middle, thinning 

 out on all sides to the thinness of cardboard. ]\Iore than twelve 

 hundred specimens in which more or less of a calyx was shown 

 were obtained from this deposit. The arms of these Crinoids 

 are so mingled in the slab that it was impossible to free any of 

 them, but some of them have been traced to a distance of forty 

 inches from the body to which they belong. 



The slab which the Museum has received from Mr. Springer 

 shows distinctly at least sixty-five bodies, while fifteen or sixteen 

 more can be made out under the covering of entangled arms. 

 The body or calvx had thin walls, the plates of which were ap- 

 parently connected by a sort of articulation or loose suture, so 

 that it was more or less flexible and comparatively light in 

 weight. All the calices have been flattened so that the opposite 

 walls have been brought together in the form of a watch crystal. 



E. o. H. 



THE DEPARTMENT OF PUBLIC INSTRUCTION. 



]W0 letters which have been recently received by 

 Professor Bickmore give very gratifying evidence 

 of the spreading influence of the Department of 

 Public Instruction under his control. Persons who 

 are in the habit of attending the lectures at the 

 Museum know the popularity of the courses by Professor Bick- 

 more and appreciate the superb character of the views thrown 

 on the screen, but the extent to which these lectures and views 

 are being used in the public schools of the State and the demand 



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