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. sphezrophora, Kiitz. 
Fresh water. Gloucester: Occasional in meadow ditches ‘at 
Mullica Hill, and Burlington: Marlton. 
N. stauroptera, Grun. (WN. leptogongyla, Ehrb., var. stawroneiformis, 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. 
N. 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. . trinodis of Lewis has the 
central lobe much larger than the others. It is doubtful whether 
the two are really distinct species. 
N. Troghus, 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. 
