KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND I[8. w:o 5. 15 
Length 0,088—0,109 mm. Breadth 0,008—0,009 mm. 
Pi. IT, fig. 46, 7°77. 
Balearic Islets rare (F. SOpERLUND). 
‘\ 
Among the Stauroneis forms, known to me, there are two, which have a similar 
structure: St. Stodderi Lewis and St. Stodderi var. insignis Gruy., both freshwater spe- 
cies. St. sulcata is marine and has finer strie. 
3. Stauroneis Africana Cr. N. Sp. 
Valve very convex, hyaline, elongate. Stauros reaching the margins. Strie fine, 
23 in 0,01 mm., parallel, reaching the median line. 
Length 0,05 mm. Breadth 0,01 mm. 
PL. TM, tig 42 Gs Vig BBY 
Fresh, or very slightly brackish water, Zwathrops River, Port Elisabeth, South 
Africa in a sample sent by Mr. W. Josaua (Cx. and Méxt. Diat. N:o 196). 
This form is nearly related to S. salina W. Sm., but has finer striez. ‘The striae 
of S. salina are 17 in 0,01 mm. 
4. Stauroneis pachycephala Cr. N. Sp. 
Linear, gibbous in the middle and at the ends, which are broadly rounded and 
capitate. Strie oblique, very fine, about 29 in 0,01 mm., reaching the median line. 
Stauros reaching the margin. Median line straight. Terminal nodules turned in oppo- 
site direction. 
Length 0,055 mm. Breadth 0,009 mm. 
Pi. U1, fa, 48 ie 
Fresh or slightly brackish water, Baakens River, Port Elizabeth, South Africa in 
4 sample sent by Mr. Josaua (Cx. et Motu. N:o 197). 
This species comes nearest to St. desiderata Cu. (in Cu. et Grun. Arctische Diat. 
Pl. III, fig. 58), which also has the terminal nodules turned in opposite direction, but 
the outline of this species is different and its striae are almost parallel and much 
coarser. Both belong to a section parallel with Grunows section Pseudopleurosigma 
of Navicula. 
5. Stauroneis (Pleurostauron) Sagitta Cu. N. Sp. 
Elongated, apiculate, to the outline resembling St. Smithii Grun. Ends with short 
interior diaphrams as in Pleurostauron. Strie oblique 21 in 0,01 mm. one or two in 
the middle very strong. 
Length 0,03—0,04 mm. Breadth 0,006—0,01 mm. 
Pl. TH tg 45 Py 
Fresh water, mouth of Tana Elf, Finmarken, collected by Prof. Ta. M. Fries 
(Cu. et Méxu. Diat. N:o 261 not rare). 
