KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 27. N:0 3. 157 



This species has a close resemblance to M. Smithii, from which it is however distinguished 

 by the longitudinal lines close to the median line. The following three species are nearly akin to 

 M. baltica and all may perhaps more properly be considered as varieties of M. apiculata. 



63. M. Citrus Cl. (1883). — V. broadly elliptical, apiculate. L. 0,o3 to 0,o4; B. 0,oi6 to 

 0,024 mm. Loculi about 9 in 0,oi mm., of equal size, quadrate, forming a band reaching to the 

 apiculi. Striae 18 or 19 (middle) to 23 (ends) in 0,oi mm. slightly radiate. — M. baltica var.? 

 Citrus Cl. Vega p. 495 PI. XXXV f. 7. M. suborbicularis Lbud. Fortm. D. de Malaisie p. 19 

 PI. II f. 6 (1892)? M. Citrus A. S. Atl. CLXXXVII f. 16 to 19. Icon. n. PI. II f. 6. 



Marine: Adriatic! Labuan! Sandwich Islands! Vera Cruz (Atl.), Jamaica (Grove Coll.)! 



64. M apiculata W. Sm. (1856). — V. elliptic-lanceolate, frequently rostrate. L. 0,o5 to 

 0,09; B. 0,023 mm. Loculi 7 to 8 in 0,oi mm. equal, quadrate, forming a band, ending near the 

 extremities. Median line straight, enclosed between two approximate longitudinal ribs. No areas. 

 Striae 15 to 19 in 0,oi mm., almost parallel, finely punctate; puncta 19 to 23 in 0,oi mm., forming 

 fine, longitudinal rows. - B. D. II p. 65 PI. LXII f. 387. A. S. Atl. CLXXXV f. 43, CLXXXVI 

 f. 23. Icon. n. PI. II f. 24, 25. M. acutiuscula GrRUN. in Cl. Vega p. 495. M. angulata Perag. 

 D. de Villefr. Pl. Ill f. 22 (1888). M. balkanica Br A. S. Atl. CLXXXVII f. 40 (1893)? 



Marine: North Sea (England, Sweden)! Cherbourg (Grun.), Mediterranean Sea! Sebastopol! 

 China! 



65. M. labuensis Cl. (1883). — V. linear, with cuneate ends. L. 0,064 to 0,075; B. 0,oi5 

 to 0,016 mm. Median line straight, enclosed between two approximate longitudinal ribs. No 

 areas. Loculi 7 to 8 in 0,oi mm. equal, quadrate, forming bands reaching nearly to the ex- 

 tremities. Strife 15 to 17 in 0,oi mm. parallel, or slightly radiate towards the extremities, coarse- 

 ly punctate, puncta 17 in 0,oi mm., forming straight, longitudinal rows. — M. acutiusc. var. lab. 

 Cl. Vega p. 495 PI. XXXV f. 5. M. lab. A. S. Atl. CLXXXV f. 4? CLXXXVH f. 2. Icon. n. 



PI. n f. 5. 



Marine: Labuan! Philippines! 



66. M. Peragalli Cl. (1892). — V. elliptic-lanceolate, rostrate. L. 0,052 to0,058; B. 0,oo25 

 to 0,002 7 mm. Median line undulating, enclosed between two, not very approximate longitudinal 

 ribs. No axial area. Central area small. Loculi 8 in 0,oi mm., almost equal, rectangular, forming 

 bands, reaching to the apices and with slightly undulating interior edges. Strise 18 in 0,oi mm. 

 parallel, or slightly radiate towards the ends, punctate; puncta about 20 in 0,oi mm., forming 

 straight, parallel, longitudinal rows. — M. sp.? Pbrag. D. Villefranche p. 44 PI. Ill f. 23. M. Perag. 

 Cl. Diatomiste I p. 160 PI. XXIII f. 7. 



Marine: Mediterranean Sea (Perag.), Sumatra (Deby Coll.)! Japan! 



67. M. Pisciculus Cl. (1894). — V. lanceolate, subacuminate. L. 0,035; B. 0,oi5 mm. 

 Median line sinuose. Axial area indistinct. Central area orbicular, small. Loculi 4 in 0,oi mm., 

 quadrate, equal, forming a marginal band, ending below the extremities of the valve. Strise 21 

 in 0,0 1 mm. almost parallel, radiate at the ends, finely punctate, puncta forming longitudinal rows. 

 The strise are crossed by a longitudinal line at some distance from the median line. The strise 

 inside the longitudinal lines faint. — Diatomiste II p.. 55 PI. Ill f. 2. 



Marine: Pensacola (Grove Coll.)! 



68. M. pumila Grun. (1880). — V. elliptic-lanceolate. L. 0,025 to 0,028; B. 0,oi mm. 

 Central nodule large, quadrate, prolonged into narrow horns, parallel to the margin. Loculi 6 to 

 8 on each side, of unequal size, the median being largest. Strise 23 in 0,oi mm. parallel. — M. 

 Braunii var. pumila Grun. V. H. Syn. p. 71 PI. IV f. 23. A. S. Atl. CLXXXV f. 36, 37. 



Slightly brackish water: Baltic (Dannf.), Hawaii! 



