. Annual report. New York State Museum; Science; Science. 164 NEW YORK STATE MUSEUM largely by interpolation in the older part of the shell and by splitting in the anterior portion. Ten or 12 spines are scattered over the sur- face of the shell and several crowded on the ears. Posterior part of the valve marked with concen- ~~*—^ trie wrinkles becom- I I ' I ing stronger near the ears. The interior of ?o , . . „ the valve has tne Productus tenuicostiformis nov. Cape le Trou, Grindstone i. muscular attachments well developed and sharply defined as is revealed in a cast; anterior adductors attac
. Annual report. New York State Museum; Science; Science. 164 NEW YORK STATE MUSEUM largely by interpolation in the older part of the shell and by splitting in the anterior portion. Ten or 12 spines are scattered over the sur- face of the shell and several crowded on the ears. Posterior part of the valve marked with concen- ~~*—^ trie wrinkles becom- I I ' I ing stronger near the ears. The interior of ?o , . . „ the valve has tne Productus tenuicostiformis nov. Cape le Trou, Grindstone i. muscular attachments well developed and sharply defined as is revealed in a cast; anterior adductors attached to low indistinct ridges; diductors attached to four or five low bilobate or looped ridges on either side of the ad- ductors. Brachial valve more nearly subquadrate than the pedicle valve, the hinge being about equal to the anterior width of the shell. Valve nearly flat over the visceral region, somewhat depressed in the central region and elevated around it, geniculated at the margin (un- less surrounded by a wall). Beginning at the ears a very narrow platform extends outward enlarging as it passes around the sides to the anterior of the valve where it has the width of a millimeter or more. Mesial septum reaching well toward anterior part of valve. Adductor attachments nearly round but showing a tendency to digi- tate lobation. Cardinal process bilobate at least below, as shown in cast. Dimensions. Length of shell, 14 mm; width, 18 mm; length of hinge, 19 mm; 9 or 10 striae in 5 mm. Remarks. The horizontal platform surrounding the visceral area of the brachial valve is of unusual interest since it occupies the posi- tion of the murication in, Marginifera. No murication is, however, preserved in our specimens, though it could hardly be expected that it would be, and there is little to lead one to suspect that such muri- cation did exist. The generic disposition of the shell is not quite clear. The cardinal process is bilobate, below at least, as in Pro- ductella, though
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