PLATE XXXIX 



PAGE 



Figs. 1.5. LOPHOSPIBA BICINCTA (Hall) 294 



1. A perfect, silicified shell. 



2. Portion of the last whorl of same, showing direction and regularity 



of lines of growth. X 2. 



3. Right side of last whorl of Fig. 1. 



Ordovician (Chazyan), Stones River Is., Murfreesboro, Ten- 

 nessee. 



4. A large cast of the interior on which some of the external lines of 



growth are obscurely preserved. 



Ordovician (Chazyan), Black River group, Beloit, Wisconsin. 



5. Vertical section of an elongated specimen. 



Ordovician (Chazyan), Black River group, Dixon, Illinois. 



Figs. 6-8. BUCANIA SULCATINA (Emmons) 309 



6. Side view of a large individual. 



7. View of a specimen. X 2. 



8. A young individual. X 6. 



Ordovician (Chazyan), Lake Champlain area. 



Figs. 9-11. AMPYX (LONCHODOMAS) HALLI (Billings) 337 



9. Head with rostral spine broken. 



10. Pygidium with two of thoracic segments. 



11. Side view of head. 



Ordovician (Chazyan), Highgate Springs, Vermont. 



Figs. 12-15. MACLUBITES MAGNUS Lesueur 297 



12-14. Top, side, and botttom views of same specimen, two-thirds 



natural size. 



15. Interior view of an operculum, two-thirds natural size. 

 Ordovician (Chazyan), Lake Champlain area. 



Fig. 16. LEPERDICIA FABULITES Conrad var 364 



Surface of slab with numerous examples of this variety. X 1.3. 



Ordovician (Chazyan), Stones River group, Lebanon Is., 

 Columbia, Tennessee. 



Figs. 1-5 are after Ulrich and Scofield; 6-8, 12-14 are after 

 Raymond; and 9-11 are after Billings. 



389 



