142 PALEOZOIC PALEONTOLOGY. 
MONOTRYPA GLOBOSA Nl. Sp. 
Plate VIII., Figs. 4-6. 
Description.—Zoarium subglobular, 12 to 20 mm. in diameter, base 
or point of attachment small, the direction of the central zocecial 
tubes nearly straight, the lateral ones strongly curved outward and 
then downward, the intermediate ones becoming progressively more 
and more curved from the centre to the sides. Internally, as shown 
in tangential sections, the zocecia are rather thick walled, and their 
duplex character can be readily seen. They are polygonal in outline, 
and acanthopores are lacking. Mesopores of variable size are present, 
from none at all to three being in contact with each full-grown 
zocecium ; they are more abundant among groups of somewhat thicker- 
walled zocecia. As shown in longitudinal section, the mesopores are 
but the initial portion of normal zocecia, which rapidly increase in 
size to their normal condition, because of the rapid spreading of the 
tubes, due to their strong curvature towards the sides of the zoarium. 
Diaphragms are scarce, there rarely being more than a single one in 
the entire length of a zocecial tube, while many tubes are apparently 
entirely free from diaphragms. 
Remarks.—This species has not been found very commonly in the 
Trenton limestone of New Jersey, but it is quite distinct in its char- 
acters. It may always be recognized by its strongly-curved zocecial 
tubes and the small number of diaphragms. The surface characters 
of the species have not been determined, because all the specimens 
observed are firmly imbedded in the matrix. The groups of thicker- 
walled zocecia with more numerous mesopores, seen in the trangential 
sections, were probably somewhat elevated above the surface as mon- 
ticules. 
CALLOPORA sp. undet. 
Pilate VII., Fig. 5. 
Fractured specimens of Callopora are occasionally met with in the 
Trenton limestone of New Jersey, but they are always in a poor 
state of preservation, and their specific identity cannot be made out 
with any degree of certainty. The members of this genus of bryozoa 
have a more or less dendritic zoarium, with subcylindrical branches. 
