ats PALEOZOIC PALEONTOLOGY. 
or circular, sometimes subtriangular or trilobate; diameter 0.30 mm.; 
space between adjacent apertures equal to or less than the diameter of. 
an aperture. Anterior margin shghtly elevated, posterior side strongly 
elevated, with two shght denticulations. Surface with shghtly-— 
elevated monticules.”—Hall. 
MONOTRYPA SPHAERICA (Hall). 
Plate XXVI., Figs. 9-11. 
188%. Favosites sphericus Hall, Pal. N. Y., vol. VI., p. 9, pl. ‘7, figs. 
1-12, pl. 8, fig. 8. . 
Description.—Zoarium massive, subhemispheric or explanate in 
form, with monticules situated at distances of about 5 mm. Zocecia 
polygonal, thin walled, the larger ones 0.5 mm. in diameter and the 
smaller ones less than 0.25 mm. In the thin, tangential sections the 
monticules are represented by groups of larger zocecia, with a few much 
smaller ones interspersed, which appear as scattered mesopores. From 
the centres of these groups the size of the zocecia gradually diminish 
to the middle of the interspaces, where the smallest ones occur. The 
diaphragms are flat and horizontal, averaging about two tube di- | 
ameters apart, though frequently they are much closer together. 
Remarks.—More than one distinct form has probably been confused 
in Hall’s species, Favosites sphericus. Most of the specimens illus- 
trated by him undoubtedly represent a species of Monotrypa, but others 
seem to be a true Favosites. In New Jersey the species occurs in the 
coral bed at the base of the Coeymans limestone. 
BRACHIOPODA. 
STROPHEODONTA VARISTRIATA (Con.). 
Plate XXXVIL., Hig. 4. 
See, also, p. 261. 
Description —The shell usually identified as this species from the 
Coeymans limestone is somewhat different from most of its Manlius 
limestone representatatives. They are usually larger and more 
