208 NAVICULA. 



N. integra W. Sm. (S.B.D., ii., p. 96 ; H.V.H. Atl., pi. n, f. 22* ; 



in Type No. 55), plate 4, fig. 174. 



Valve lanceolate elliptic, margins with 3-7 undulations, apices abruptly 

 rostrate-apiculate. Raphe surrounded by a narrow hyaline zone ; median 

 stria? straight, distant, producing a pseudo-stauros under low magnification, 

 then radiate, 23 in 1 c.d.m. Length, about 3 c.d.m. Breadth, about 1 c.d.m. 



Slightly brackish water. Antwerp, Blankenberghe. England, Scotland, Ireland, Holstein. 



This may possibly be, according to Grunow (Arc. Diat., p. 36), only a 

 simple variety of N. crucicula, which is a protean form analogous to JV. mutica. 



N subinflata Grun. (in Cleve Vega, p. 470, pi. 37, f. 50*), 

 plate 27, fig. 760. 



Valve linear, more or less elliptic, somewhat inflated at the median portion 

 with obtuse, rounded apices. Stria? almost perpendicular to raphe, 19 in 

 1 c.d.m. ; the twc or three central ones somewhat shortened and very distant. 

 Girdle face rectangular with connecting zone showing fine longitudinal lines. 

 Length of valve, 2*5 to 4 c.d.m. Breadth, 8 mill. d.m. 



Marine. Norway, Grip ; Cape Wankerema. 



var. elliptica. -Valve more elliptic (Adriatic, Cleve and Moll Diat. 

 No. 210). 



IX. Palpebrales. 



Valve with hyaline zone very elongate, lanceolate ..... N. palpebralis. 



N. palpebralis Breb. (in w. Sm., S.B.D., i., p. 50, Supp. pi. 31, 



f. 273 ; H.V.H. Atl., pi. 11, f. 9* ; Type No. 116), plate 4, fig. 175. 



Valve broadly elliptic-lanceolate, with apices acute, slightly mucronate ; 

 stria? radiate, rather robust, not punctate, marginal, leaving round the raphe a 

 broad hyaline space, lanceolate in form. Stria? vigorous, about 10 in 1 c.d.m. 

 Breadth, 4*5 to 5 c.d.m. Length, 7*5 c.d.m. 



Marine. Ostend, Blankenberghe (H.V.H.). Mouth of the Scheldt (Thomson). On all the 

 North Sea Coasts. 



var. obtusa (H.V.H. Atl., pi. n, f. 8*), plate 4, fig. 176. 



Apices somewhat constricted, very obtuse. 



Marine. Blankenberghe, 



