PLATE 29. 
Trionyæ rivosus. 
Fig. 
1. Outside view of hinder half of the carapace, nat. size. 
pla—pls. The fourth to the eighth costal plates inclusive. 
2. Inside view of the same specimen. 
pla—pls. The fourth to the eighth costal plates inclusive. 
5—9. The ribs (fifth to the ninth dorsal inclusive) connate with the above costal 
plates. 
s6. The neural arch confluent with the sixth neural plate. 
