PLATE 1. 



Fig. 1. 1. 1. SCOLITHUS LINEARIS. ( Pag. 2.) 



1 a. A vertic;il or longituilinal view of a specimen of the rock containing these hoilieg. 



1 6. A similar view of a specimen of partially altered and laminated sandstone from I'ennsylvania, the tubes 



somewhat flattened. 

 I c. Weathered surface of a specimen of the altered sandstone (crystalline or granular i(narl/.)i from Adams, 



Massachusetts. 



Fig. 2. 



2. 1. LiNGULA PRIMA. 



(Pag. 3.) 



Fig. 3. 3. 2. LlNGULA ANTIQUA. (Pag. 3.) 



.1 a. The usual form of this fossil. 



3 6. A l)roader specimen, with ajiex wanting. 



'I c. A very hroad somewliat rounded specinn-n, a view of the interior of the shell, the inner laminir wanting, 



and the concentric elevated lines showing in relief. 

 .■3 il. An elongated specimen, somewhat compressed laterally. 

 •'I c. An etdarged portion of 3 c. 



