KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 27. N:0 3. 105 



blank band across tlie strise. Strise on the dorsal side 10 to 11 in 0,oi mm. coarsely punctate; 

 piincta abont 8 in 0,oi mm., often uniting near tlie central nodule. — A. lihyca Ehb. Ber. 1840 

 p. 11 (fide Kiltz). Kutz Bac. p. 107. A. affinis Ktixz Bac. p. 107. A. ovalis rar. affinis V. H. 

 Syn. p. 59 Pl. I f . 2. A. ovalis A. S. Atl. XXVI f. 102 to 111; Pl. XXVII f. 4, 5? A. abbre- 

 viata Blbisch Rabh. A. E. 1489 (1863). A. Szontaglm Pant. II p. 39 Pl. VII f. 138? A. Frotnis 

 var. A. S. Atl. XXVHI f. 1? A. Staubii Pant. III Pl. X f. 171 (1893)? A. verrucosa Pant. III 

 Pl. X f. 166 (1893)? A. sravls Pant. III Pl. XXVIII f. 416 (1893)? 



Fresh or brackish water: Spitsbergen (Atl.), (rreenland! East Cape! Sweden! England! 

 Erance! Belgium (V. H.), (xermany (Saline Dllrrenberg! Königsberg, foss.!) Hungary foss. (Pant.)? 



Var. Pediculus Kutz (1844). — Frustule in ontline broadly elliptical. Valve lunate. L. O, o 2 

 to 0,04; B. 0,006 to 0,008 mm. Median line slightly biarcuate. Central area distinct and central 

 nodule strong. Striai 14 to 16 in 0, 01 mm. coarsely pnnctate. Ven trål side striate. — Cymhella? 

 Pediculus Kutz Bac. p. 80 Pl. V f. 8. A. ovalis d Pediculus V. H. Syn. p. 59 Pl. I f. 6. A. ovalis 

 y affinis f. minor {A. Pediculus major Grun.) V. H. Syn. p. 59 Pl. I f. 4, 5. A. minnfissima "W. Sm. 

 B. D. p. 20 Pl. II f. 30 (1853). A. horealis Schum. P. D. I Nacbr. p. 23 f. 31 (1863). A. glohosa 

 ScHUM. P. D. II Nacbr. p. 55 Pl. I f. 24 (1867). A. .sp. n.? A. S. Atl. XXVI f. 102. A. lihyca var. 

 interrupia Pant. II p. 37 Pl. II f. 28. 



Fresh or sligbtly brackish water, nsually attached to larger diatoms, as Nitzscbia sigmoidea, 

 or on algse: Sweden! Finland! England! Belgitim! Germany! India (Atl.), New Zealand! Tasmania! 

 Hungary, fossil (Pant.). 



Altbough these varieties are at first sight very dissimilar to eacb others, they are so inti- 

 mately conuected by intermediate forms tbat I am entirely of the opinion of Grunow and Van 

 Heurck tbat they sbould be united. 



13. A. perpusilla Grun. (1880). — Fru-stule in outline nearly orbiciilar. L. 0,oo6 to 0,oi; 

 B. 0,004 to 0,005 mm. Valve liinate, with arcuate dorsal, and straight ventral, margin. Central 

 nodule strong. Dorsal strise 16 to 20 in 0,oi mm. almost transverse. Central area usually not 

 distinct. Ventral side withoiit strise. — A. (globulosa var.) perpusilln Grun. V. H. Syn. Pl. I f. 11. 



A. 2>erp. V. H. Types N:o 4. A. ovalis var. 6 Pediculus forma minor and exilis V. H. Syn. p. 59 

 Pl. I f. 8, 9, 10. A. Pediculus A. S. Atl. XXVI f. 99. Cl. M. D. 126, 137. A. globulosa Schum. 

 Preuss. D. II Nachr. p. 55 Pl. I f. 25. A. S. Atl. XXVI f. 100. 



Fresh water, moist earth etc: Sweden (Upsala, Dalsland!) Prussia (Schum.), Belgium (V. H.), 

 England, Swansea! France, Meudon! Hungary, Plattensee (Atl.). 



14. A. mexicana A. S. (1875). — V. lunate with arcuate dorsal and straight ventral mar- 

 gin. L. 0,15 to 0,20 ; B. 0,0.35 mm. Median line more or less biarcuate. Axial area not distinct; 

 centra] area small and rounded on the dorsal side. Dorsal side with a longitudinal line more or 

 less approximate to the median line. Strise 6 to 8 in 0,oi mm. coarsely punctate; puncta 6 to 7 

 in 0,01 mm. Ventral side entirely covered with somewhat radiate strise. — A. S. Atl. XXVII 

 f. 47 to 48. Icon. n. Pl. IV f. 15. A. boryana Pant. IH Pl. XXXVIII f. 531 (1893). 



Marine: Morocco! Gulf of Naples! Sumatra (Deby CoU. !), China! txalapagos Islands! Gulf 

 of Mexico (Atl.). 



Var. fusca Cl. — Zone with small irregular puncta giving it a brownish colour. L. 0,i4; 



B. 0,0 7 5 mm. Strise 8 in 0,oi mm. 



Marine: Macassar Straits! 



I am not quite sure about the Identification, as the fig. in Atl. shews a more distant 

 longitudinal line than in my specimens. A. Urna A. S. Atl. Probetof. f. 14, which is unknown to 

 me, seems to be allied to A. mexicana. 



15. A. gigantea Grun. (1875). — Frustule broadly elliptical with truncate ends. V. lunate, 

 with straight ventral margin. L. 0,o9 to 0, 17; B. 0,o25 to 0,o35. Median line strongly biarcuate. 



K. Sv. Vet. Akad. Handl. Baucl 27. N:o 3. 14 



