258 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 57 



limestone layer ; that their growth has begun from a point below, and rapidly 

 expanding upwards, has often extended one or two feet in diameter, as 

 now shown upon the exposed surface of the limestone bed. At a single 

 exposure on the farm of Mr. Hoyt, the surface of the limestone is covered by 

 these bodies for many rods in extent. The entire area of the cellar beneath 

 the house of Mr. Hoyt is upon this bed of limestone closely covered by these 

 hemispheric masses with concentric structure. For a distance of one or two 

 miles to the southward the outcrop of this limestone can be traced, and every- 

 where presenting the same characters in the presence of these masses. Large 

 numbers of specimens of various sizes have been weathered out and lie 

 scattered over the surface. This fossil has also been found at Little Falls, 

 Herkimer County, New York. 



These bodies have long been known under the name of Stromatopora, from 

 their general resemblance in form and structure to that fossil ; but their posi- 

 tion in reference to the bedding of the rock is uniformly the reverse of that of 

 Stromatoporae, which occur in the higher limestones, growing from a broad 

 base which is covered by an epitheca, while these bodies under consideration 

 grow upward and expand from a point below, while the convex surface is 

 on the lower side. A careful examination of the nature of these bodies proves 

 that while having the concentric structure common to Stromatopora they have 

 not the regular succession of layers of tubuli characteristic of the species of 

 that genus and cannot properly be included under that term. I, therefore, 

 propose the term Cryptozoon as a designation for this peculiar form and 

 mode of growth which will be more fully elucidated in the future. 



CRYPTOZOON PROLIFERUM Hall 



Plate Z7, figs. 1-3 



Cryptozoon proliferum Hall, 1884, Thirty-sixth Ann. Rept. New York State 

 Mus. Nat. Hist., desc. of pi. 6. (Species defined in description of 

 plate as below, and illustrated by plate 6.) 



The original description is as follows : 



These bodies are made up of irregular, concentric laminae of greater or 

 less density and of very unequal thickness. The substance between the con- 

 centric lines, in well-preserved specimens, is traversed by numerous, minute, 

 irregular canaliculi which branch and anastomose without regularity. The 

 central portions of the masses are usually filled with crystalline, granular, 

 and oolitic material and many specimens show the intrusion of these extraneous 

 and inorganic substances between the concentric laminae. That these are 

 intrusions, and not inclusions, is shown from the fact that they can be traced 

 to a vertical fissure or break leading to the exterior of the fossil and which 

 ■allowed the crystalline matter to enter. 



Formation and locality. — Upper Cambrian : (76) Arenaceous Hoyt 

 limestone at Hoyts quarry, 4 miles (6.4 km.) west of Saratoga 

 Springs, Saratoga County, New York. 



