219 



radiate, finely divided transversely and interrupted near the margin of the 

 valve by a rather broad depression, of which the margins have the appearance 

 of double sulcus. Length, about 14 c.d.m. Breadth, 4 c.d.m. 



Brackish water. Rare, Antwerp (H.V.H.). The type form does not appear to have yet been 

 found in any other part of Europe. The forma parva has been found at Schleswig, and a var. by 

 Kitton at Breydon, Norfolk, England. 



N. amphisbaena Bory. (Encyciop. Method., 1824; h.v.h. 



Atl., pi. 11, f. 7*; Type No. 130), plate 5, fig. 203. 



Valve broadly elliptic, with apices strongly rostrate capitate. Central 

 nodule lateral, terminal nodules robust. Raphe surrounded by a considerable 

 hyaline zone, dilated in the middle of the valve into a broad space lanceolate- 

 subquadrangular. Stria; radiate, about 14 in 1 c.d.m., finely divided trans- 

 versely, interrupted by a rather broad submarginal sulcus. Length 6 to 7 

 c.d.m. Breadth, 225 c.d.m. 



Fresh or somewhat brackish water. Antwerp, &c. Throughout Europe. 



var. subsalina. (H.V.H. Atl., pi. 11, f. 6* ; Type No. 131), plate 

 5, fig. 204. 



Apices gently acuminate, not rostrate capitate. 



Brackish water. Banks of the Scheldt at Antwerp. England. 



forma major. (H.V.H. Atl., pi. 11, f. 4*), plate 5, fig. 205. 



Much larger, valve lanceolate, infinitesimally attenuate as far as the 

 apices, which are very gently acuminate. Length, 10 c.d.m. Breadth, 

 about 3 c.d.m. 



Brackish water. Scheldt at Antwerp. 



var. Fenzlii. (H.V.H. Atl., pi. 11, f. 5*), plate 5, fig. 206. 



Valve broader, with apices scarcely acuminate. 



XVII. Limosae. 



f No pseudo stauros, valve with three well marked inflations . . N. limosa. 



Valve with three inflations slightly marked . N. ventricosa. 



{ 



A pseudo stauros 



Valve linear, without inflations . . N. fontinalls. 



N. limosa KlltZ. (Baa, p. 101; H.V.H. Atl., pi. 12, f. 18*; Type 

 No. 135 : Caloneis Silicula (Ehr.) CI.); plate 5, fig. 207. 



Valve narrow, linear, with three undulations, equal, feeble, with rounded 

 apices. Raphe surrounded by a lanceolate hyaline zone, somewhat enlarged 

 at the median portion. Ctntral nodule somewhat lateral; terminal nodules 



