NIAGARA GROUP. 
131 
some of them, however, I have been able to detect several vertical lamellae, but without any 
transverse septa. The whole is so minute that these lamellae may prove to be tubular and not 
celluliferous. 
The coral presents a variable surface appearance, from the different influences of weathering ; 
when it has suffered little or nothing from such causes, the entire surface presents a series of 
stars having a depression in the centre, and apparently confluent at the margins ; where it has 
been slightly weathered or worn, the stars are limited, and in many cases there is a solid 
crystalline centre with surrounding fays. A polished transverse section presents the cells with 
a space between them equal to the diameter of the cell. A vertical section gives the same 
general appearance. 
This species has not the cells as well defined with the tubular or cellular interstices as the 
following, and in this respect does not precisely meet the requirements of the generic character 
as given by Mr. Dana. It seems, however, to differ too little to require reference to any other 
genus. 
Fig. 1 a. A portion of the surface, showing the openings of the cells. 
Fig. 1 b. A vertical section produced by weathering. 
Fig. 1 c. Enlargement of 1 a, showing the variable appearance of the cells. 
Fig. 1 d. Enlargement of 1 b, showing the cells as they appear when weathered. 
Fig. 1 e. A magnified view of a polished transverse section. 
Fig. 1 /. A magnified view of a polished vertical section. 
Fig. 1 g. A magnified view from the lower side of the coral. 
Position and locality. In the lower part of the Niagara limestone at Lockport. 
(State Collection) 
520. 2. HELIOLITES SPINIPORA (n. sp.). 
Pl. XXXVI. Fig. ‘Z a- n. 
Compare Pdrites tubulata, Lonsdale : Murchison, Sil. System, p. 687, pl. 16, fig. 3. Also 
fig. 2 a, b , of Porites pyriformis, id. ib. 
Turbinate, pyriform, hemispheric and spheroidal masses, formed of diverging cylindrical 
tubes with cellular interspaces, often rapidly increasing by interstitial additions of new tubes, 
and thus becoming spheroidal; openings of the cells upon the surface circular, with twelve 
short rays, not confluent; spaces between the openings cellular; tubes transversely septate, 
and externally marked by strong longitudinal striae. A longitudinal section shows cellular in¬ 
terspaces, and the interior of the tubes often crowded by spiniform rays nearly meeting in the 
centre. 
This coral presents such a variety of appearance and character, that it is impossible to give 
an adequate description in a few words. It occurs mostly in small hemispheric or spheroidal 
masses, and its great variety of aspect is mainly due to weathering and the effects of different 
conditions of crystallization of the mass. In many specimens the exterior limits of the cells 
are not conspicuous, and the stellate openings appear to be confluent or nearly so. In such 
