248 The Ohio Journal of Science [Vol. XVII, No. 7 



Stricklandinia (?) louisvillensis, Nettelroth. Plate X, Figs. 7A,B- 



1889. Stricklandinia louisvillensis, Nettelroth, Kentucky Fossil Shells, p. 65, 

 pi. 34, figs. 31-34. 



Brachial valve from 20 to 23 millimeters in length, with maximum 

 convexity between one-fourth and one-third of the length of the valve 

 from the beak. This convexity equals about 5 millimeters, and there 

 is a tendency toward flattening anteriorly. Low and broad plications 

 mark the valve medially and along the anterior margin, where frequently 

 they are three millimeters in width, varying to two millimeters on the 

 sides of the valve. In one specimen the plications along the median 

 part of the valve are conspicuously narrower than the remainder. 

 Toward the beak and along the postero-lateral parts of the valve the 

 plications become obsolete. The hinge-area apparently was low, and 

 the beak did not curve beyond the plane of junction of the two valves. 

 Two sharp parallel narrow ridges, about one millimeter apart and 

 eight millimeters in length, extend forward from the beak, on the 

 interior of the valve, and are interpreted as crural ridges, terminating 

 posteriorly at what appear to be triangular crural plates. 



Three valves, from the Cedarville dolomite at the eastern 

 Mills quarry, southwest of Springfield, Ohio, of which two are 

 figured here, closely resemble the type of Stricklandinia 

 louisvillensis, preserved in the U. S. National Musuem. 



The two parallel crural ridges of the brachial valves here 

 described do not suggest a spiriferoid shell, nor would they be 

 expected in a species of Stricklandinia. They might occur, 

 however, in a pentameroid shell. It is evident that more 

 material is needed for the elucidation of the affinity of these 

 shells. Nothing is known of the interior of typical Strick- 

 landinia louisvillensis, as found in the Lousiville limestone at 

 Louisville, Kentucky. Only the exterior of the type is known, 

 and in this the beaks of both valves are closely appressed and 

 no delthyrium is seen. Its generic relationship remain uncertain. 



Two pedicel valves, having about the same size and form as 

 Stricklandinia louisvillensis, and marked by similar low broad 

 plications, were found in the Cedarville dolomite at Cedarville, 

 Ohio. They dififer however, in other particulars. The cardinal 

 area has a height of at least three millimeters; the beak has a 

 correspondingly greater prominence, and probably extended 

 considerably beyond the beak of the brachial valve although 

 only moderately incurved. The sides of the open delthyrium 

 form an angle of about 40 degrees. There is a faint depression 

 along the median part of the shell, its sides forming an angle of 

 about 20 degrees with each other. This depression is almost 



