KONGL, SV, VET. AKADEMIENS HANDLNGAR. BAND 27. N:0 3. 139 



Subgenus Arohiamphora. 



Frustule unknown. Valves as in Calamphora, but the ventral side is without longitudinal 

 lines, and has a row of short stritE or puncta, either along the median line or between the median 

 line and the margin. 



The species of this subgenus are all found in a fossil state at Oamaru, New Zealand, always 

 as detached valves. Yet they bear a considerable likeness to the forms of Calamphora, so that it 

 is possible that the zone may be complex; and, indeed, in specimens of A. fimbriata fragments of 

 the zone are found which tend to show that it is similar to those of the subgenus Calamphora. 



Artificial key. 



j Costae 4 to 5 in 0,oi mm ... . . . .3. 



1. < — 6 to 7 — — . . A. fimbriata Cl. a. Grove. 



I — • 11 — — . . . . A. antiqua Cl. a. Geove. 



Puncta 9 in 0,oi mm. . . . . A. rectilineata Cl, a. Grove. 



— 11 — — A. prisca Cl. a. Gkove. 



[ 



1. A. antiqua Cl. a. G-rove N. Sp. — V. linear, with obliquely rounded ends. L. O.is; 

 B. 0,013 mm. Dorsal side with parallel costate strise, 11 in 0,oi mm., alternating with rows of 

 puncta, 24 in 0,oi mm. Ventral side smooth, with a longitudinal median row of short striae, 

 11 in 0,01 mm. 



Marine: Oamaru, New Zealand, fossil (Grove Coll.)! 



2. A. rectilineata Cl. a. Grove N. Sp. — V. linear with obliquely rounded ends. L. 0,09; 

 B. 0,015 mm. Dorsal side with parallel costEe, 4 in 0,oi mm., alternating with double rows of 

 puncta, 9 to 10 in 0,oi mm,, forming longitudinal rows. Ventral side smooth, with a median band 

 of short, puncta-like striae, 6 in 0,oi mm. — PI. IV f. 24, 25. 



Marine: Oamaru, New Zealand, fossil (Grove Coll.)! 



3. A. fimbriata Cl. a. Grove N. Sp. — V- linear with obliqely rounded ends. L. 0,14 to 

 0,18 mm. Dorsal side with parallel striae, 6 to 7 in 0,oi mm. Ventral side with a row of short 

 striae, close to the median line. 



Marine: Oamaru, New Zealand, fossil (Grove Coll.)! 



4. A. prisca Cl. a. Grove N. Sp. — V. linear, with obliquely rounded ends. L. 0,i4 to 

 0,16; B. 0,016 to 0,022 mm. Dorsal side with parallel costate striae, 4 to 5 in 0,oi mm. Inter- 

 mediate spaces transversely lineate; lineolae 11 in 0,oi mm. Ventral side with a row of short 

 radiate striae along the median line, otherwise structureless. 



Marine: Oamaru, New Zealand, fossil (Grove Coll.)! 



Additional. 



Amphorce, ivhich cannot for the present he grouped in any of the above subgenera. 



1. Amphora elegans Pbrag. (1894). — Frustule elongated, narrow, with slightly convex 

 margins and truncate ends. L. 0,09; B. 0,oi5 mm. Zone not complex V. narrow lunate, acute. 

 L. 0,08; B. 0,01 mm. Central nodule dilated into a stauros. No areas and no longitudinal lines. 

 Strife equidistant on the dorsal and ventral side, 22 in 0,oi mm. distinctly punctate; puncta 25 

 in 0,01 mm. arranged in straight longitudinal rows. — Temp. a. Perag. Types N:o 414. Diatomiste 

 II p. 56 PI. Ill f. 8. 



Marine: Cabours. 



This remarkable species has the same structure as the Naviculae of the section Orthostichee 

 and might be considered as an asymmetrical form of this section. 



