panamic-pacific pelecypoda 501 



Explanation of Plate 28 



Figure Page 



1. JTeocyreua tribunalis (Prime) 19S 



Length 55 mm. Tucames River, Ecuador. Prime Coll. Holotype, 

 MCZ 176888. 



2-2d. Neocyreua fortis (Prime) 197 



Figs. 2, 2a, length 46.1 mm. Ecuador. Prime Coll. Paratype, Smith- 

 sonian Institution 11616; Fig. 2b, length 52.1 mm. Ecuador. Prime 

 Coll. Paratype. MCZ 187454; Figs. 2c, 2d, length 40 mm. Coji- 

 menes, Ecuador. PRI 25708. 



3. Neocyreiia tiiaiigula (von du Busch) Philippi 197 



(N. olivacea Carpenter). Length 58.3 mm. Mazatlan, Mexico. 

 USNM 86811. 



4-4b. JTeocyrena meridionalis (Prime) 198 



Length 34.7 mm. Tumbez River, Peru. Lea Coll. USNM 122451. 



5-5b. JTeocyreiia radiata (Hanley) 198 



Fig. 5, length 31 mm. Guanico, Panama. PRI 125709; Figs. 5a, 5b, 

 length 36.8 mm. Realejo. Nicaragua. Stearns Coll. USNM 98552. 



6. Polymesoda (Polymesoda) uotaWlis (Deshayes) 192 



A beach worn specimen with the periostracum and outer chalky 

 layer removed. Length 54 mm. Sua, Ecuador. P'RI 25710. 



7-7a. Neoeyreiia sp 199 



Length 34.6 mm. mouth of the Guarara River, Panama. J. Zetek. 

 ANSP' 155424. 



