FRESHWATER AND LAND SHELLS. 55 



Two M. undulata. Without charged oviducts. 



One An. undulata, with reddish charged oviducts, displaying, in a 

 beautiful manner, the honej'comb appearance. 



Jan. 18, 1835. — Re-examined a keg of Naiades, received from T. 

 G. Lea, two years since. Found An. Ferussaciana to be charged in 

 its oviducts like An. undulata. One U. calceolus partly charged, and 

 one fully charged. One U. parvus, thickened along the edge of the 

 oviduct, but did not appear to be perfectly developed. One An. edeti- 

 tula was found charged like An. undulata. 



Jan. 25, 1835. — Opened a large keg from T. G. Lea, taken near 

 Cincinnati. U. cornutus was found to differ in its form of the ovi- 

 ducts from other species, the sacks being inclined, and lying parallel to 

 each other, and pendent to the posterior part of the branchiae only. U. 

 trigonus, animal of a deep nearly red colour. U. *Msopus, orange co- 

 lour. U. cylindricus, colour pale orange with a blackish line along 

 the lower part of the foot. U. securis was found with the oviducts 

 like cariosus. Sym. complanata, colour fine orange. U. ovatus, very 

 like to cariosus in the oviducts. Sym. gracilis, oviducts like cariosus, 

 but much finer and closer. U. triangularis, oviducts small and some- 

 what like cariosus, but more oblong and bent in. U. foliatus had 

 small oviducts. 



U. clavus,* found the animal to be orange colour. 



U. retusus, has oviducts on the posterior part of the branchiae only ; 

 they resemble those of cariosus, but are smaller. 



U. ellipsis. The oviducts are like retusus. 



U. orbiculatus, has oviducts like cariosus. 



U. rectus, has oviducts close to the posterior end. 



March, April, May 1835. — During these months numerous speci- 

 mens were examined, which confirmed my previous observations. 



May 26 — I opened a keg containing various species, from Cincin- 

 nati the preceding autumn. 



Twenty An. Ferussaciana. Seventeen had charged oviducts. 



Four An. incerta were apparently all males. 



* Scalenius? (Rafinesque). 



