552 axel a. olsson 



Explanation of Plate 79 



Figure Page 



1. Hastasia melanura (Sowerby) 448 



Figure after Sowerby in Thesaurus, 1849. 



2. Parapholas calra (Sowerby) 447 



Figure after Sowerby in Thesaurus, 1849. 



3. Parapholas acuminata (Sowerby) 447 



Figure after Sowerby in Thesaurus, 1849. 



4-4d. Hastasia tnbifera (Sowerby) 448 



Figs. 4, 4a, length 44.7 mm.; Fig. 4b, length 30.4 mm.; Fig. 4c, 

 broken tube of the siphonoplax showing the inner wall partitions; 

 Fig. 4d, shell in its bore in a piece of shale, length 30 mm. Manta, 

 Ecuador. PRI 25929. 



5-5a. Hastasia esmeraldensis, new species 449 



Length 25.7 mm., Esmeraldas, Ecuador. Holotype, ANSP 218949. 



6. Martesia (Martesia) striata (Linne) 446 



Length 24.4 mm., Venado Beach, Panama Canal Zone. PRI 25930. 



7-7a. Martesia (Martesia) striata (Linne) 446 



Fig. 7, Hiatella stage, length 17.7 mm.; Fig. 7a, adult, side view, 

 length 24.4 mm. Venado Beach, Panama Canal Zone. PRI 25930. 



