512 THE AMERICAN NATURALIST. [VoL. XXXIV. 
B’. Divisions of rostrum long and sharp M. acuticornis Stimpson, G 
Genus Stenocionops Leach. 
Key to Species. 
4. Carapace with strong median n 
S. spinosissimus (Saussure), M( CH) 
A’, Carapace without a d median spines. 
B. Carapace smooth . ce w 0. o. 39. fercaius COW 
Fic. 7. — Pitho anisodon. 
B’. Carapace tuberculous S. furcatus celatus (A. Milne-Edwards), G 
Genus Macrocœloma Miers. 
Key to Species. 
A. Carapace ith d l spi besides th il hial d posterior spines. 
B. Rostrum strongly defiexed M. septemspinosum (Stimpson), SG 
