2/16 PALEONTOLOGY OF NEW-¥ORK. 
tubes present a beautiful stellate 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. | 6. A transverse section of the cells, showing the starlike extremities. 
Fig. 1c. 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 have 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. CHATETES LYCOPERDON. 
Pu. LXXV. Figs. 2 a, b,c, d, e, f. 
Reference pag. 64, pl. 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 tamose 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, 6. The bases of two hemispherical forms, where the tubes have a barely perceptible extension. 
Fig. 2c. A fragment of a ramose form, one of the largest occurring in this group. 
Fig. 2 d. A subhemispheric form, which commenced its growth upon the column of a crinoid. 
Fig. 2 e. A fragment of stone, with several ramose forms associated with a crinoidal column, a small 
Murchisonia and Orthis testudinaria. 
Fig. 2 f. 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 Collection.) 
