276 PALAEONTOLOGY OF NEW-YORK. 



tubes present a beautiful strllate appearance, and the mass is often as open and free from 

 the infiltration of mineral matter as in the recent corals. In weathered specimens, the 

 sides of the tubes show the remains of the vertical and transverse partitions of the adjoining 

 cells. 



Fig-. 1 a. A fragment of this coral, showing a vertical section, with an oblique section of the extremities 



of the tubes. 

 Fig. 1 b. A transverse section of the cells, showing the starlike extremities. 

 Fig. 1 c. An enlarged view of the extremities of several cells. 



Position and locality. This species is scarcely known in New^York, a few obscure speci- 

 mens being all that I liave observed in the shaly parts of the Hudson-river group. In the 

 western extension of the same formation it is abundant, and developed in large spheroidal 

 and hemispheric masses. At Madison, Indiana, this species forms two distinct layers near 

 the top of the shales of this group, occurring in masses of from one to three feet in 



diameter. (State Collection.) 



101. 2. CH^TETES LYCOPERDON. 



Pl. LXXV. Figs. 2 a, b, c, d, e,f. 

 Reference pag. 64, pi. 23 and 24 of this report. 



This coral acquires its full development in the shaly part of the Trenton limestone, 

 rarely appearing in hemispheric forms in the succeeding shales. In the more calcareous 

 part of the Hudson-river group it occurs in ramose forms, similar to those already described, 

 and assumes some other features in its mode of growth not observed in the limestone. 

 Notwithstanding the fact that it is rarely or never found in the hemispheric form, the 

 animal appears often to have commenced its growth in this way, and to have discontinued 

 it, probably from unfavorable circumstances, while the slender branching forms are 

 numerous in the same situation. 



Fig. 2 a, h. The bases of two hemispherical forms, where the tubes have a barely perceptible extension. 



Fig. 2 c. A fragment of a ramose form, one of the largest occurring in this group. 



Fig. % d. K subhcniispheric form, which commenced its growth upon the column of a crinoid. 



Fig. 2 c. A fragment of stone, with several ramose forms associated with a crinoidal column, a small 



Murchisonia and Orthis testudinaria. 

 Fig. 2/. Magnified section of a ramose form, showing the columns to be nearly parallel to the axis of 



the specimen. 



Position and locality. This species occurs throughout the Hudson-river group, particularly 

 in the calcareous strata ; and though assuming a somewhat different aspect from the same 

 species in the Trenton limestone, is nevertheless identical. The principal localities are 

 Turin, Lewis county ; Loraine, Jefferson county; Pulaski, Oswego county; and it is also 

 found in numerous other places. (State Co/lection.) 



