ÖFVBRSIGT AP K. VETENSK.-AKAD. FÖRHANDLINGAR 1900, N:0 8. 931 



lyradiatus Castr. 1. c. PI. III f. 4. — Podosira {Micropodiscus) 

 Oliveriana Grun. Van Heurck Syn. PI. CXVIII f. 8. — Janisch 

 Exp. Gazelle PI. XX f. 3, 5]. This form, characteristic for 

 the antarctic region, occurred sparingly in almost all saniples from 

 45^ S. 11° E. to 43° S. 57^ E. 



Coscinodiscus sol Wallich. At 37' S. 23° W. and more 

 or less common from 43' S. 71° E. to 32' S. 91° E. 



Coscinodiscus Trompii Cl. N. Sp. Valve thin-walled, con- 

 cave, diara. 0,05 to 0,08 m, ra., finely punctate; puncta of equal 

 size, forming straight, radiate fasciculate rows, 10 in 0,01 m.m. 

 Fasciculi composed of about 20 rows; their number about 9. 

 The border with a row of small, soraetimes indistinct, apiculi, 

 4 or 5 in 0,01 mm. 



Fig. 9. Entire frustnle. 

 500 t. m. 



Fig. 10. 



a. The centre. b. The border af 

 the valve. 1000 t. m. 



This species has some resemblance to the arctic C. {Tha- 

 lassiosira) polychordus Gran, but the valve of the latter is plane, 

 and I have not seen the frustules united by slime-threads. The 

 fasciculate arrangement of the rows of puncta is sometimes not 

 apparent on smaller specimens, on which they cross each other 

 as in C. Uneatus, but the rows are much closer than in this 

 species. Found in samples from 44° S. 9° E. to 44° S. 41° E., 

 in some abundantlv. Fis. 9, 10. 



