PLATE XXVII—Continued. 
Stylonurus (?) (Echinocaris?) Wrightianus. 
Page 160. 
Fig. 7. Dorsal view of the type specimen of Eqidsetides Wrightianus, Dawson. The specimen consists 
of two abdominal somites of this crustacean, presei-ved as an internal cast in sandstone and 
. showing'the pustulose ornamentation, the conspicuous ridges along the posterior margin of 
each somite and the character of the articulation between the somites. On the anterior surface 
of the last somite several longitudinal impressions are seen, apparently made by the long 
posterior spines of the preceding somite. 
Fig. 8. Side view of the same specimen, showing the charactei- of the articulation, the strong marginal 
ridges and the smooth ventral surface. The specimen has been slightly flattened, vertically 
making the convexity of the somites somewhat less than it should normally be. 
Fig. 9. An enlai'gement of the surface to show the character of the oniamentation. 
Portage group. Italy, Yates county. 
Echinocaris punctata. 
Page 166. 
See Plates 28 and 29. 
Fig. 10. An enlargement of the sui-face of an abdominal somite from the specimen i-epresented on plate 28, 
fig. 4. Introduced for comparison with the preceding figui'e. 
Hamilton group. Tichenori''s Point, Canandaigua Lake. 
