442 GEOLOGICAL SURVEY OF NEW JERSEY. 



N. semicruciata, Weissflog. 



Fresh water. Occasional in the same localities as the pre- 

 ceding species. 



N. seminulum, Grun. 



Fresh water. Morris : Occasional in Budd's Lake, and Glou- 

 cester : Mullica Hill Pond. 



N. servans (Breb.), Kiitz. 



Fresh water. Atlantic : Common in ponds at Absecon and 

 Hammonton. Morris : Fossil at Drakesville. 



N. Smithii, Breb. 



Salt or brackish water. Monmouth : Common in sand rip- 

 ples near the mouth of Shark River and of Manasquan River. 

 Atlantic : Brackish ditches at Absecon. 



N. spheerophora, Kiitz. 



Fresh water. Gloucester : Occasional in meadow ditches at 

 Mullica Hill, and Burlington : Marlton. 



N. stauroptera, Grun. (N. leptogongyla, Ehrb., var. stauroneiformis, V. H.) 



Fresh water. Camden : Common in cranberry bogs and 



ponds at Ancora and Kirkwood, and Gloucester : Mullica Hill. 



N. Tabellaria, Ehrb. 



Fresh water. Common in meadow ditches and grassy pools 

 throughout the State. 



1^. trinodis, Lewis. 



Fresh water. Occasional in ponds and ditches. Camden : 

 Blackwood, Kirkwood and Camden. Gloucester : Mullica Hill 

 and Woodbury. Sussex : Hamburg. Associated with this is 

 often found the N. trinodis of Wm. Smith, which has the valve 

 divided into three equal lobes. N. trinodis of Lewis has the 

 central lobe much larger than the others. It is doubtful whether 

 the two are really distinct species. 



N. Trochus, Ehrb. 



Fresh water. Camden : Rare in the blue clay of the Dela- 

 ware River at Philadelphia Lewis. 



N. tumida, Rab. (Scoliopleura, Breb.) 



Salt or brackish water. Atlantic : Abundant in pools on the 

 marshes near Absecon and Atlantic City. Cape May : Occa- 

 sional in Dennis Creek. 



