PLATE VI 



TUIAUTIIIIL'S 13ECK1 Gkeex (I'.uies 199-20i') 



Figure 1. — Dorsal view of larva. X -8. 



FiGUiiE 2. — Dorsal view of young individual, willi one free llioracic 

 segment. (After Walcott.) 



Figure 3. — Ceplialon with autennaj nearly at right angles to axis. 

 The thorax and pygidiuni are omitted in figures 3-0. The figures are 

 enlarged 3-5 diameters. 



Figure 4. — Cephalon with ant(>nna3 bent outward and liackward. 



Figure 5. —Cephalon with sliglitly diverging antennae directed for- 

 ward, — the usual position in the majority of specimens. 



Figure 6. — Cephalon with antennae curving backward between the 

 eyes. 



Figure 7. — Dorsal view; showing antennae and crawling and swim- 

 ming legs. X 3. The legs on the left side are taken from a smaller speci- 

 men and are enlarged 6 diameters. 



Figure 8. — Appendages attached to right side of second and third 

 thoracic segments; taken from another speciuKMi. 



Figure 9. — The same; with setae omitted from //, to show details 

 of structure; ea;, exopodit(^; e», endopodite. The setae are represented 

 on ///. X 12. 



Utica Slate, Ordoviciau, near Koine, New York. 



