GASTROPODA— PLEUROTOMARIIDM. 



t>37 



Guelph of Canada and New York, Upper Monroe of Michigan 

 and Canada. 



108. L. adjutor (Hall). (Fig. 863.) Devonic. 

 Whorls of round aspect ; periphery depressed ; band concave, 



margined by two spirals ; shoulder and body carinae nearer to pe- 

 ripheral band. 



Onondaga of New York and Ohio. 



109. L. trilix (Hall). (Fig. 864.) Devonic. 



^^^HS(86S&r<r 



FlG. 863. Lophospira adjutor. 

 (After Hall, Pal. N. Y., V.) 



Fig. 864. Lophospira trilix, X 2 - 

 Y.,V.) 



(Pal. N. 



Peripheral band tricarinate ; shoulder with strong median or 

 supra-median and sometimes faint sutural carinae ; body with two 

 close set carinas crossed by later whorls ; growth lines strong, 

 lamellose. 



Hamilton of eastern New York, Pennsylvania, Maryland, etc. 



XXXII. Schizolopha Ulrich. 

 Like Lophospira, but with the apertural notch prolonged into 

 a long slit with parallel edges, 

 no. S. moorei Ulrich. (Fig. 865.) Ordovicic. 



Fig. 865. Schizolopha moorei ; a, lateral, and />, umbilical, view of internal mold ; c, 

 specimens with shell preserved. All X %■ (After Ulrich, Pal. Minn.) 



Apical angle about 75 ° (more or less); whorls embracing to 

 within one half or one third shoulder width of the angle ; shoulder 

 and body free from spirals, gently concavo-convex ; slit occupying 

 about one fifth of length of last whorl. 



Lorraine and Richmond of the Cincinnati dome region. 



