^^ 143 



The sutural laminse are half the width of the tegmentum. 



Width of valve, 20 mm. The length of the dorsal area is 5 mm.; 

 divergence, 130°. 



The generic position of this species is doubtful, but the thin- 

 ness of the shell and the angle of divergence lead one to conclude 

 that it rightly belongs to the above genus. 



14. Chiton, sp. indet. 

 Two median valves from Muddy Creek. 



Lateral Area. — Distinctly raised, the anterior margin being the 

 most elevated. Three or more deep concentric growth lines cross 

 the area. A very shallow radial ribbing is distinctly present 

 near the girdle, but it disappears as the jugum is approached. 



Pleural Area. — This area is ornamented with imbricating 

 longitudinal ribbing. These ribs are strong near the girdle, but 

 become shallower as they approach the jugum. The jugum is 

 much worn. 



Measurement. — Width, 8 mm.; length, 4 mm.; divergence, 80\ 



15. Chiton, sp. indet. 

 One specimen anterior valve. 



Slope strongly convex. 



Shell polished, the only ornamentation being about 20 shallow 

 concentric ridges. 



Inside. — The articulamentum is crossed laterally by a strong 

 ridge. The pectination of what remains of the insertion plate is. 

 most pronounced. 



16. Chiton, sp. indet. 



One median valve from Muddy Creek. 



Lateral Area. — Much broken away, slightly raised, sculptured 

 with strong broken longitudinal ribs. 



Pleural Area. — Ornamented with shallow, but distinct longi- 

 tudinal ribbing, the interspaces being twice the width of the ribs. 



Dorsal Area. — Much worn. 



Measureme7it. — Width, 8 mm.; length, 4 mm.; divergence, 95'. 



17. Loriea, sp. indet. 



Two median valves from Muddy Creek, both much worn. 



Decidedly carinated, side slopes slightly curved. 



The Lateral Areas are raised, and contain three or four deeply 

 marked radial sulcations, converging at the apex. 



The Pleu7'al Areas have from eight to ten deep longitudinal 

 ridges, gradually lessening in width towards the girdle. 



The Dorsal Areas are too much worn to admit of description. 



Length of Dorsal Area. — One valve 11 mm., the other 8 mm.; 

 width, 23 mm. and 20 mm. respectively ; divergence, 90° and 95°. 



