104 Trans. Acad. Sci. of St. Louis. 



margin regularly curved throughout its entire length ; poste- 

 rior extremity situated well towards the dorsal margin, its 

 margin rather abruptly rounded. Beak prominent, incurved, 

 elevated above the hinge-line, situated about two-sevenths of 

 the length of the shell from the anterior extremity. Surface 

 marked by concentric wrinkles which are most conspicuous 

 anteriorly. 



Remarks. The specimen selected as the type of this species 

 was included among the '* types " of Grammy sia amygdalinus 

 (Win.), in the University of Michigan collection. This 

 specimen, however, along with two others associated with it, 

 is entirely different from the real type of the above mentioned 

 species, as determined from Winch elFs original description 

 and the dimensions given by him. These specimens, there- 

 fore, have to be considered as representatives of an unde- 

 scribed species. The genus to which these specimens should 

 be referred is uncertain since the characters of the hinge can- 

 not be seen. The species is provisionally referred to the 

 genus Glossites, for the want of any better place for it, 

 though with the feeling that when the hinge-characters are 

 known, it will have to be removed. It differs from Gram- 

 mysia amygdalinus in its larger size, in its less convexity, in the 

 absence of any well-defined umbonal ridge, and in the more 

 dorsal position of the posterior extremity of the shell. 



Promacrus cuneatus Hall. 



PI. IV.f.20. 



This species has not been observed but it was described 

 from the ** yellow sandstone" at Burlington* and possibly 

 belongs in the Chonopectus sandstone fauna. The illustra- 

 tion is a copy from the original one published by Hall. A 

 nearly complete specimen from the Vermicular sandstone at 

 North view, Missouri, has been identified f with this species, 

 but the Burlington shell is much more slender anteriorly than 

 the North view specimens. 



* See Pal. N. Y. 5^ : 510. pi. 78. f. 28. 



t Trans. St. Louis Acad. Sci. 9 : 36. pi. 3.f. 2. 



