"[illegible] Three have the same internal structure but are immensely small, the diameters of the smallest and largest specimens being respectively 3 and 5 mm." Micropora spong., p 37. This is a small gregarious globular calcareous sponge free and having no spicules. Its structure is firm or minutely firm, and very compact. Weather worn specimens show the firm structure which is well illustrated in the figure, Mincepor sections, given and by Dr. J. G. Grant, reveal what we suppose to be spicules. They are minute needle shaped bodies. This species is sometimes found in clumps, though it is by no means a common fossil. Specimens collected vary in diameter from less than one eight to more than one half an inch, and have been found at Cincinnati, and in the upper part of the Gimp. The specimen above noted is from the collection of C.B. Dyer. Animalides reticulatus, Murry, p 92. The thirty five payments before me were found on a spot about two feet square, and it may be possible that they all belong to one individual, but that seems scarcely probable. They are all hollow and the envelope is composed of an aggregation of sub cylindrical or rather club shaped stems which are placed parallel with each other, and perpendicular to the surface; their inner ends are acutely pointed, while that end which shows on the exterior surface is rounded, and with a minute port on the tip, for the articulation of two very fine and gun all spines. The distribution of these club shaped plates is very regular, being arranged in curved or flexuous transverse, and diagonally intersecting lines; and an account of their cylindrical form, they are a great number of interstices which may be referable to pores analogous to those of the Anteriidea.