NIAGARA GROUP. 
123 
513. 3. ASTROCERIUM PYRIFORME {n. sp.). 
Pl. XXXIV A. Fig. la - e. 
Irregularly subturbinate, pyriform or spheroidal • cells angular, radiating from a more or 
less extended base, often from a narrow area, spreading out above and rapidly increasing by 
the addition of interstitial tubes; tubes opening upon the surface by well defined angular 
mouths, which are seen of all sizes and forms, from triangular to hexagonal, in their different 
stages of development; cells within divided by transverse septa, and one or more rows of fine 
spiniform rays between each pair of septa. 
This species presents but slight differences from the last, and may perhaps be only a variety 
of the same. The most obvious difference appears in the openings of the cells upon the surface, 
which are usually smaller than in the preceding species, more uniformly angular, and do not 
present the larger nearly round openings which occur at intervals in the last species. It is often 
difficult, from any external character, to discover any distinction between this fossil and some 
species of Favosites ; but a careful examination of the internal structure has shown, in nearly 
all instances, the peculiar stellate structure and spiniform rays. 
Fig. 1 a. A spheroidal form of this species. 
Fig. 1 b. A turbinate form, the cells increasing rapidly from a narrow base. 
Fig. 1 c. An irregular turbinate form of larger size. 
Fig. 1 d. A portion enlarged, showing the internal structure of the cells. 
In this individual both the septa and rays are nearly obliterated, but enough re¬ 
mains to decide the generic characters of the species. 
Fig. 1 e. An enlarged portion from the inner walls of the cells, showing the granulated or pa¬ 
pillose surface from the bases of the spiniform rays. 
The specimens figured above are nearly solid throughout, the cells being filled to the openings, 
so that the stellate structure is very obscure, though evidently existing in all the specimens 
figured. 
Position and locality.. This species occurs in the shale of the group at Rochester, Wolcott 
and Lockport, and more rarely in the limestone at Rochester and Lockport. (State Collection.) 
514. 4. ASTROCERIUM CONSTRICTUM («. $p.). 
Pl. XXXIV A. Figs. 2 a - c, and 3 a - e. 
Massive, hemispheric; cells minutely stellate; coral dividing into columns, which appear 
as if constricted at intervals. 
This species has the columns a little larger than Chcetetes lycoperdon , and more strongly 
constricted at intervals. These characters alone are sufficient to distinguish it on careful com¬ 
parison, though from a cursory examination it would easily be mistaken for that one. When 
the ends of the cells are visible, however, there is no difficulty in distinguishing the true cha- 
