54 DESCRIPTION OF NEW 



Twenty-four U. ochraceus. Ten were found to be females, fourteen 

 males. 



Six Margaiitana undulata. One was found to be a female, five 

 males. 



One Margaritana marginata. Sex female. 



Four Anodonta undulata. One was found to be a female, three 

 males. 



Six Anodonta Jluviatilis. Three proved to be females, three males. 



Oct. 23, 1834. — Opened a fine specimen of Mar g. marginata and 

 found the oviducts forming a lobe like the »^n. Jluviatilis, there being 

 no apparent sacks, but the whole mass was largely distended. The foot 

 and surrounding portions were found to be of a salmon colour, as well 

 as the edge of the mantle, which diminishes in intenseness as it ap- 

 proaches the sides and back. The perfect shells could be observed, 

 but they were not so far advanced as to be yet brown. 



Opened five specimens of Marg. undulata. Only one had charged 

 oviducts, which were found to be similar to the above, but not quite 

 so far advanced. Termination of the foot slightly salmon colour. 



Opened two U. ochraceus. One male, the other female. The lat- 

 ter fully charged. 



Nov. 16, 1S34. — Examined three specimens of U. eariosus, all ob- 

 tuse at posterior end. — Found them all fully charged. 



Two U. ochraceus. Obtuse. Fully charged. 



One U. radiatus. Obtuse. Fully charged. 



One U. nasutus. Obtuse. Just commenced to swell on the bor- 

 der of the branchiae. 



Two U. complanatus. Both males. 



Two M. undulata. Both males. 



Two An. Jluviatilis. One male, one female. 



Dec. 24, 1834. — Opened the following shells, which had been kept 

 in water some four, some twelve weeks, in the house. 



Four U. eariosus. One female, three males. 



Three U. complanatus. All without charged oviducts. 



Two M. marginata. Without charged oviducts. 



