238 ALLAN HAXCOCK PACIFIC EXPEDITIONS VOL. 20 



PLATE 11 



Fig. 1. Area mulahiits (Sowerby) 1833. Puerto Parker, Costa Rica. 



Dorsal view showing narro^v ligamental area. Length, 30 



mm. 

 Fig. 2. Irca mutahilis (Sowerby) 1833. Isla Isabel, Gulf of 



California. Dorsal view showing very wide ligamental 



area. Length, 32 mm. 

 Fig. 3. Barbatia lurida (Sowerby) 1833. Isla Espiritu Santo, 



Gulf of California, a. Outside of right A'alve. b. Inside of 



the same. Length, 28.7 mm. 

 Fig. 4. B. {Cucullaearca) reevcana (Orbigny) 1846. Isla Angel 



de la (juarda, Cnilf of California. Detail of periostracum. 



Length, 70 mm. 

 Fig. 5. B. {Cucullaearca) reeveana (Orbigny) 1846. Off Punta 



Pequena, Baja California, a. Outside of right valve of young 



specimen, b. Dorsal view of the same. Note that the liga- 

 ment is behind the umbones. Length, 10.3 mm. 

 Fig. 6. B. (Fuffleria) illota (Sowerby) 1833. Puerto Utria, 



Colombia. Inside of left valve. Note the obsolete teeth in 



the middle of the hinge. Length, 38.1 mm. 

 Fig. 7. B. (Fugleria) illota (Sowerby) 1833. Off Puerto Escondido, 



Gulf of California. Inside of left valve. Note the more 



ovate form. Length, 23 mm. 

 Fig. 8. B. (Fuglcria) illota (Sowerby) 1833. Bahia Octavia, 



Colombia. Hinge of young specimen with continuous row 



of teeth. Length, 13.2 mm. 

 Fig. 9. B. {Cucullaearca) reeveana (Orbigny) 1846. Isla Wenman, 



Galapagos Islands. Young specimen with yellow prodisso- 



conch. Length, 2.7 mm. 



