CHAZY LIMESTONE. 15 



CORALS AND CRINOIDEA OF THE CJIAZY LIMESTONE. 



Plate IV. 



18. 1. RETEPORA INCEPTA. 



Pl. IV. Figs. 1 a, b. 



A thin expanded Icaflike coral, apparently composed of branches uniting laterally and 

 often irregularly ; fenestrules oval or sometimes slightly angular, unetjual in size ; branches 

 er reticulations even, roundish, scarcely expanded ; no pores visible. 



This species presents the common appearance of others of the genus, except that the 

 above fragment shows no axis or central point of expansion, and in this respect resembles 

 a fragment of Gorgonia. In the irregular arrangement of the fenestrules, it differs from 

 any of the species yet noticed. 



Fig. 1 a. Specimen of the natural size. 

 Fig. 1 b. An enlarged portion of the same. 



Position and locality. In the semi-oolitic limestone near the lower part of the mass at 

 Chazy, and in a similar limestone near Galway, Saratoga county. 



19. 2, RETEPORA GRACILIS ( 71. 5^.). 



Pl. IV. Figs. 2, 2 a. 



Expansion slender, diverging ; fenestrules oblong-oval ; branches or interfenestral spaces 

 slender, flexuous, slightly striated ; no pores visible. 



This species differs from the last in its more slender appearance, the greater length of 

 the fenestrules, and the smaller interfenestral divisions. The crust or expansion is less firm 

 and solid. The nature of the stone almost effectually prevents the discovery of any pores 

 upon the substance of the coral. The rock in which this and the preceding species occur 

 is a semicrystalline greyish limestone, cxliibiting in some parts a tendency to an oolitic 

 structure. 



Fig. 2 a. Natural size of the fragment. 



Fig. 2 b. Enlarged portion, showing the form of the fenestrules: 



Position and locality. This species occurs in the lower part of the Chazy limestone, below 



the position of the Maclurea gigantea, at the village of Chazy, Clinton county. 



(Stalt Collection.) 



