Weller — Kinderhook Fanned Studies. 19 



size of that species, in being more gibbous with a less sharply 

 defined mesial sinus, and with a larger number of plications 

 nearly all of which bifurcate near the beak. The shell 

 seems to approach most nearly to S. striatiformis Meek, and 

 is provisionally identified with that species. One of the spec- 

 imens resembles somewhat closely Hall's figure of S. subro- 

 iundatus (Geol. Surv. Iowa 1^, pi. VII. f. <9^) described from 

 the ** Chemung Group " at Burlington, la. 



Spirifer sp. 



This species is represented in the collection by numerous 

 fragments, but by no specimens sufficiently well preserved to 

 allow a complete description and illustration. It has the gen- 

 eral form of S. suhorbicularis from the Osage fauna, but it is 

 always much smaller, rarely or never growing to be more than 

 20 mm. in length. It is more or less subcircular in outline, 

 with a short hinge-line; the fold and sinus are well defined to 

 the beak and are nearly or quite free from plications ; the 

 plications on the sides of the shell are simple, rather broad, 

 and flattened. The species occurs in other Kinderhook faunas, 

 both older and younger than the present one, and will be 

 more fully described and illustrated at another time. 



Spirifer sp. 



Several more or less imperfect specimens have been found, 

 of a small species of this genus about 10 or 12 mm. in breadth, 

 having an elongate hinge-line with angular or mucronate car- 

 dinal extremties, a smooth well-defined sinus and simple plica- 

 tions on the sides of the shell. It has not been possible to 

 identify it with any described species, and it is consequently 

 left until more perfect specimens can be secured, for descrip- 

 tion and illustration. 



Spiriferina sp. 



Several specimens altogether too imperfect for description 

 or illustration, probably belong to this genus. They have the 

 general form of other members of the genus, and are charac- 

 terized by their subangular plications and their conspicuous 

 concentric lamellae of growth. 



