758 
17. OVALIS. (Kg.) Breydoii, Hunstanton, Brancaster. 
N. PALPEBRALis. (Sill.) Wells, Hunstanton, and Brancaster 
Sands. 
N. PEREGRiNA. Elir. Breydoii ditches ; common in brackish- 
water localities. 
H. PERMAGNA var. (Bailey.) Breydoii. 
N. PLACENTULA. Elii'. Osier Car, Heigham. 
H. PUNCTATA. (Kg.) Heigham, Whissonsett. 
H. pusiLLA. Osier Car, Heigham. 
H. RADiosA. (Kg.) Ormesby,^ Paniham, Horning, Whissonsett, 
Costesse}'’. 
N. RADiosA var. acuta. (Grun.) Ormesby. 
H. RECTANGULATA. (Greg.) AVells, Hunstanton, and Brancaster 
Sands. 
H. RETUSA. (Breb.) Wells. 
H. RHOMBOiDES. Elir. Edgefield, Ormesby, Whissonsett, Flordon. 
N. RHYNCOCEPIIALA. (Kg.) Elordoii, Wliissoiisett. 
H. SALINARUM. (Gruii.) Breydoii. 
H. scuLPTA. Ehr. Breydoii. 
H. SCUTELLOIDES. (Greg.) Ormesby. 
H. SERIANS. (Kg.) Edgefield Heath ; frequent in fresh-water 
gatherings. 
H. SPHAEROPHORA. (Kg.) Wliissoiisett : very plentiful, frequent 
in fiesh-water ditches, -this species is the “ Oat-animal ” 
of W. Arderon, who found it in “Spring Gardens,” Norwich, 
in 1754 (see Baker’s “Employment for the Microscope”); 
previously to this only two species of Diatomacetc had been 
discovered. 
H. SUBIMPRESS A. Gruii. Breydoii. 
H. SUBSALINA. (Donk.) Breydoii, Yarmouth, Lynn. 
N. UNDOSA. Ehr. Ormesby Broad ; Osier Car, Heigham. 
H. VARiANS. (Greg.) Osier Car, Heigham ; Whissonsett. 
jST. viridis. (Sin.) Common in all fresh-water gatherings. 
H. viRiDULA. Ehr. Eorma parva. Breydoii. 
Genus Scoliopleura Grunow. 
S. CONVEXA. (Sm.) Wells, Breydoii. 
S. TUMiDA. (Breb.) Wells, Hunstanton, Lynn, Breydoii. 
S. Westii. (Sill.) Wells, Yarmouth. 
