KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND. 18. N:0 5. 17 



Surirella Turpin. 



1. Surirella Caldensis Cl. N. Sp. 



Very long and slender, linear, with cuneate ends. Ala3 high. Canaliculi short, 

 numerous, 4 — 5 in 0,01 mm. Margin striate; striaj punctate 20 in 0,01 mm. F. V. 

 linear, not cuneate. 



Length 0,108 mm. Breadth 0,013 mm. 

 Pl. IV, fig. 50, ""7i. 



Brazil, Caldas on Sphagnum (Dr. Hj. Mosén). Cl. et Moll. Diat. N:o 212, 

 common. 



This species comes near to *S. arcta A. Schm. Atl. Pl. 23, lig. 23 — 24 from De- 

 merara, but its canaliculi are shorter and denser. 



2. Surirella degenerans Cl. N. Sp. 



Oblong, with very broad ends and slightly contracted middle. Margins striate. 

 Costse obsolete, consisting only of the dilated portion. Area with some scattered mar- 

 kings and strite. 



Length 0,09—0,072 mm. Breadth 0,037—0,046 mm. 

 Pl. IV, fig. 51, ^°7x. 



Gallapagos Islands (Eugenie Exp.). 



This form, which belongs to the variable section of S. lata, is related to S. läxa 

 Janisch. 



3. Surirella formosa Cl. N. Sp. 



Panduriform with large, rounded ends. Margin striate. Costas abbreviate, with 

 the dilated portion comparatively large. The middle of the valve is occupied by a 

 narrow linear area, defined by short striaa. 



Length 0,22 mm. Breadth 0,11 mm. at the constriction 0,07 mm. 

 Pl. IV, fig. 49, "V,. 



Gallapagos Islands extremely rare (Eugenie Exp.). 



This very": large and beautiful Surirella does not agree with any of the man}' 

 lorms belonging to *S. toa-section hitherto figured. 



Campylodiscus Ehb. 



1. Campylodiscus {Ecclesianus var.?) peramplus Cl. 



Very large, costa3 numerous 4—5 in 0,01 mm., equal in length, marginal. Area 

 large with a circle of puncta and with some stellate markings. 



Diam. 0,12—0,16 mm. 

 Pl. IV, fig. 53, '''I,. 



Gallapagos Islands (Eugenie Exp.). 



K. Sv. Vet. Ak. Handl, Band. 18. N:o 6. 3 



