ÖFVERSIGT AF K. VETENSK.-AKAD. FÖRHANDLINGAR 1899, N:0 10. 971 



slightly spirally arranged ribs. Interstices finely punctate. Mouth 

 simple, without denticulatioiis. 



Length: 0,08 to 0,1 mm. Diameter of the mouth: 0,04 mm. 



Hahitat: tropical Atlantic, from at least 

 19° S. 1° W. to tlie Canaries, the Azores and 

 South America. North Equatorial, Antilles and 

 Florida currents. The Caribbean and Sai'gasso 

 Seas. Northern limit (March to October 1898) 

 41° to 42° N., exceptionally at 50° N. 12° W. 

 (June 1898). — Desmo-plankton. 



Temperature: 23,3 (mean of 65 observations, 

 max, 28, min. 13,4), exceptionally 11,7. 



Salinity: 36,09 (mean of 43 observations, max. 37,05 min. 

 34,88), exceptionally 32,51. 



Fig. 450 times magnified. 



Cyttarocylis Hebe n. sp. 



House funnel-shaped, with prolonged apical end and more 

 or less numerous (usually 12 to 16, exceptionally 27) longitu- 

 dinal, slightly spirally arranged ribs. Interstices 

 finely and closely punctate. Mouth simple, teeth- 

 less. 



Lenght: 0,17 to 0,36 mm. Diameter of the 

 mouth: 0,056 mm. 



Hahitat: common in the tropical and sub- 

 tropical Atlantic. Northern limit (July to No- 

 vember) 47°— 48° N. 9°— 41° W., southern limit 

 at least 26° S. 30° W. — The Red Sea and In- 

 dian Ocean (Dr. E. Nyman) — Desmo-plankton. 



Temperature: 17 to 28, exceptionally 10. 



Salinity: 36 to 37, exceptionally 31. 



Tar. apopliysata. The prolonged apical end 

 with a gibbosity. Else as the type. 



Hahitat: tropical Atlantic, northern limit 48° N. 26° — 30° 

 W. (May). Southern limit 26° S. 45° W. — Desmo-plankton. 



