KONGL. SV. VET. AKADEMIEN8 HANDLINGAR. BAND 27. N:0 3. 161 



87. M. seriata Cl. a. GtROVb (1891). — V. broadly lanceolate, acuminate. L. 0,06; B. 0,036 

 mm. Median line undulate. Central area small, rounded. Loculi 4 in 0,oi mm. equal, quadrate, 

 forming a band reaching to the ends. Surface of the valve with 5 to 6 shallow, longitudinal 

 furrows on each side of the median line. Strise 16 in 0,oi mm., radiate throughout, in the middle 

 alternately longer and shorter, finely punctate. — Diatomiste I p. 66 PI. X f 6. 



Marine: Macassar Straits (Grove Coll.)! 



All these species from M. Leudugeri are intimately connected. M. seriata combines them 

 with M. quinquecostata var. rhombica 



88. M. quinquecostata Grun. (1860). — V. elliptical to subrhomboid. L. 0,057 to 0,i04; 

 B. 0,022 to 0,03 mm. Median line more or less undulate. Central area small. Loculi 4 to 5 in 

 0,01 mm. almost equal, forming a band reaching nearly to the ends. Striae 16 in 0,oi mm., 

 slightly radiate, finely punctate; puncta forming close, undulate, longitudinal rows. Striae crossed 

 on each side of the median line by 2 or 3 longitudinal, narrow depressions. — Verh. 1860 p. 578 

 PI. Vn f. 8. Hantzsch D. Ostind. Arch. p. 20 f. 6. Perag. D. Villefranche PI. Ill f. 21. Navic. 

 oUvacea Leud. Forth. D. Ceylan p. 32 PL II f. 23 (1879). Mast, ohscura Leud. Fortm. 1. c. p. 36 

 PI. Ill f. 33 (1879). Navie. Egeria Pant. Ill PI. XLII f. 578 (1893)? Mast. Grunowii A. S. Atl. 

 CLXXXVI f. 1 to 7. 



Marine: Mediterranean and Adriatic Seas! Cape of Good Hope! Kerguelen's Land (Castr.), 

 Sumbava! Java! Samoa! 



Var. herguelensis Castr. (1886). — Elliptical. L. 0,o.3 to 0,045; B. 0,oi8 mm. Loculi 5 in 

 0,01 mm. Striae 27 in 0,oi mm. — M. herg. Castr. Voyage Challenger D. p. 22 PI. XV f. 11. 



Marine: Labuan! Upolu (Grun.), Kerguelen's Land (Castr.). 



Var. concinna A. S. (1893). — V. almost rhomboid. L. 0,05; B. 0,022 mm. Loculi some- 

 what unequal, forming an undulate band along the margin. Striae 22 to 23 in 0,oi mm. — M. 

 cone. A. S. Atl. CLXXXVI f. 9. 



Marine: Corsica! Pithy usian Islands! Samoa! 



Var. elongata Lexjd. Fortm. (1879). — V. narrow, rhombic-lanceolate. L. 0,iO5 to 0, iii; 

 B. 0,03 mm. Striae 15 in 0,oi mm. Puncta about 19 in 0,oi mm. forming longitudinal rows. — 

 M. elong. Leud. Fortm. D. Ceylan p. 35 PL III f. 31. A. S. Atl. CLXXXVI f. 12. 



Marine: Madagascar (Van Heurck Coll.)! Ceylon (Leud. Fortm.). 



Var. rhombica Ol. — V. rhomboid. L. 0,072; B. 0,036 mm. Median line slightly undulate. 

 Central nodule very small. Loculi 3,5 to 4 in 0,oi mm. Striae 15 in 0,oi mm., slightly radiate, 

 stronger at the margin, fainter inwards, crossed by about 4 longitudinal shallow depressions, 

 punctate; puncta about 20 in O.oi mm. 



Marine: Ceylon! Madagascar! 



M. quinquecostata is a very variable species, closely connected with all the above forms from 

 M. cruciata. More or less connected with M. quinquecostata are M. quinquecostata var. neapolitana 

 Brun (A. S. Atl. CLXXXVI f. 10), M. sinuata A. S. (1. c. f. 11), M. mauritiana Brun (A. S. 

 Atl. 1. c. f. 28), M. sansibarica A. S. (1. c. CLXXXVII f. 44), all forms, of which I have had 

 no opportunity of examining original specimens. 



Additional. 



M. Brunii A. S. (1893) — appears to be allied with M. fallax — Atl. CLXXXVIII f. 27. 



M. chersonensis A. S. (1893) — seems to be related to M. elegans, but the figure is in- 

 sufficient for identification. — Atl. CLXXXVI f. 31, 32. 



M. divergens A. S. (1893) — a characteristic form, which however I cannot class in the 

 system as the figure is not sufficient. — Atl. CLXXXVII f. 52. 



K. Sv. Vet. Akad. Handl. Band 27. N:o 3. 21 



