BULLETIN NO. 2. 



Breadtii of an average size specimen, -^^ inch ; height, y\ inch. 

 'Position and locality: From a black limestone over one of the 

 lower coal seams in Mercer countj% 111. 

 No. 2530 of the Illinois State collection. 

 Collector, A. H. Worthen. 



PLEUKOTOMARIA GIFFORDI. (p. nOV.) 



Shell small, conical, volutions about seven, spire sharply ele- 

 vated, the last volution forming less than half the entire length, 

 and ornamented below the spiral band with nine or ten revolving 

 lines, that decrease in number on the succeeding volutions. 



Spiral band concave and located a little above the middle of 

 the lower volution, and defined by two strong revolving lines, the 

 upper one of which is the strongest. There are also two or three 

 revolving lines within the spiral band, and three or four on the 

 upper angle of the volution, the last one of which is much stronger 

 than the others. 



Length VV inch; diameter of the outer volution about -^ inch; 

 spiral angle about 43^. 



This shell is nearly related to P. suhconstricta, Meek and Wor- 

 then, described and figured in Vol. II of these reports, page 351, 

 PL 28, fig. 6, but differs from that in its surface ornamentation, 

 and especially in its spiral angle. 



Position and locality : Coal Measures, Peoria county. 111. 



No. 2."35 of the Illinois State collection. 



Collector, Mr. Gifford. 



PLEUEOTOMARIA ADAMSI. (sp, nOV.) 



Shell small, trochiform, conical; length a little more than the 

 diameter of the lower volution. Volutions about six, the last one 

 flat and smooth below the spiral band ; umbilical region concave ; 

 spiral band prominent, deeply grooved, and occupying the angle 

 on the periphery of the lower volution, becoming shallower and 

 less prominent on those above. The elevations defining the upper 

 and lower margins of the spiral band are marked by one or two 

 revolving lines visible with an ordinary glass, which continue on 

 the succeeding volutions where the spiral band becomes obsolete. 



Length ^ inch ; diameter of the last volution yV inch ; spiral 

 angle about 60'^. 



Named in honor of Mr. W. H. Adams of Peoria county, from 

 whom some of the specimens were obtained. 



Position and locality : Coal Measures, Peoria county 111. 



No. 2536 of the Illinois State collection. 



Collector, W. H. Adams. 



PLEUROTOMARLA NAUVOOENSIS. (sp. nOV.) 



This form is represented in the State collection by a single 

 cast in limestone from the upper part of the Keokuk limestone 

 at Nauvoo. 



