Description of Two New Genera and Eight New Species. 43 



Dystactospongia insolens, n. sp. 



Plate II., fig. 2, view of thedower side of a specimen, showing different points of attach- 

 ment, natural size; fig. 2a, the appearance of a prepared slide for the microscope, magnified 

 about three diameters ; fig. 2b, approximate appearance when magnified 100 diameters. 



Sponge, large, irregular, somewhat hemispherical, and varying from 

 two to four or five inches in diameter. The architectural frame work 

 radiates from several different points of attachment, and divides and 

 subdivides without order, and constitutes more than two thirds of the 

 entire mass. As seen under the higher powers of a microscope, the 

 structure is vesicular throughout, and full of amceba like outlines which 

 may possibly represent spicules. The appearance to the unaided e3'e 

 is that of a massive coral, having the texture destro\ T ed b}" mineraliza- 

 * tion, a thin section, however, even without the assistance of a lens, 

 shows that it is not a coral, and the spongoid character is more and 

 more revealed under the increasing power of a microscope. Under a 

 power of 8'jO diameters, the vesicles are observed to contain numerous 

 subcircular, subelliptical, and amoeba-like bodies, with irregular out- 

 lines, but I am not able to say that they are spicuhe, or fragments of 

 such forms, though it is probable that closer stud}* and examination 

 will determine their character. 



This species was first collected by Win J. Patterson, Esq., in the 

 stone quarries, in the Hudson River Group, at Cincinnati. He collected 

 numerous specimens, some of which he presented to the author, and 

 others he preserved for his own collection. 



Pattersoma, n. gen. 



A solid, amorphous, calcareous sponge, uniform in structure, 

 vesicular, and destitute of larger canals and openings. Spicules (?) 

 The generic name is in honor of Wm. J. Patterson, of Cincinnati, an 

 energetic and discriminating collector, who first discovered the fossil, 

 and subsequently prepared specimens for microscopic examination. 



Pattersonia difficilis, n. sp. 



Plate II., fig. 3, a large specimen appearing as a cluster, natural size ; fig. 3a, view 



magnified about 100 diameters. 



Whether the original form of this sponge was globular or not, we are 

 unable to determine, but, as we find it now, it consists of a flattened, 

 irregular mass, often appearing as a cluster, but no two specimens 

 having the same form. It is vesicular in structure, and under a 

 magnifying power of 800 diameters, bodies are observed somewhat re- 

 sembling acicular crystals in the plant Fuchsia, and also a few scatter- 



