100 Cincinnati Society of N'atural History. 



four rows of deep, rounded pores or punctures: the rows increase Tdv 

 implantation as thej^ approach the po-terioi- lateral margins, where 

 they number from six to seven. 



The thorax consists of six articulations; axial lobe depressed, cou- 

 A'ex, narrow, and carr^'ing on each side between the segments two rows 

 of minute punctures; lateral lobes flat, and three times as wide as the 

 central lobe; pleurae straight, and furrowed on the outer half. 



Pygidium small, acutely semi-elliptic, being about four times as wide 

 as long, and broadly rounded in outline behind, with a raised and 

 thickened margin; axial lobe verj'' small, and composed of four ob- 

 scurely defined segments; lateral lobes each with three segments. 



Length of largest known specimen, 6 m. m. ; length of cephalic shield, 

 3.5 m. m. ; breadth of do., 7 m. m. ; length of thorax, 1.25 m. m. ; breadth 

 of do., 4.5 m. m. ; length of p^^gidium, .75 m. m. ; breadth of do., 4 m. m. 



This pretty little species is related to T. concentricus, of Eaton, but 

 may be readily distinguished by its small size, the absence of the long 

 spines from the posterior angles of the shield, and the presence of four 

 rows of punctures on the sides of the middle lobe of the thorax, as well 

 as b}^ the differences in the cephalic shield, which is comparativeh' 

 much longer, more rounded in front, and not straight, but curved back- 

 wards at the base in that species. It might be urged, that the speci- 

 mens from which the description was drawn, are the young of Eaton's 

 species, but 1 have compared them with 3'oung specimens of T. con- 

 centricvs, and found that the difterences stated are constant in both 

 the 3^oung and mature stages. 



Locality and Position. — Found in the lower part of the Cincinnati 

 Group, back of Covington, Ky., at an elevation of 100 feet above low 

 water mark at Cincinnati. 



DESCRIPTION OF A NEW GENUS AND ELEVEN NEW 



SPECIES OF FOSSILS, 

 With Remarks upon others well known, from the Cincinnati Group. 



By S. A. Miller. 



Ptilodictya magnifica, n. sp. (Plate III., fig. 1, natural size, fig. 1«, 



magnified view.) 



[l&iy .—Magnijicm, magnificent.] 



This polyzoar}' consists of a thin, explanate, tuberculated frond, 

 which rapidly and irregularly expands from the neck, that evidently con- 

 nected it to a flattened base, which was attached to some other object. 



