KONGL. SV. VET, AKADBMIENS HANDLINGAR. BAND 27. N:0 3. 119 



GrBUN. Rab. A. E. N:o 1,716 (1864). H. L. Sm. T. N:o 616. A. hyalina var. parvula Grun. Rab. 

 A. E. N:o 1,722 (1864). A. coffeiformis H. L. Sm. T. N:o 31. A. libyea H. L. Sm. T. N:o 34. 



Fresh or brackish water: Sweden (Visby, Bobuslan)! England (Kew gardens!) France (Caen!) 

 Grermany (Berlin!) Sardinia (Atl.), Nile Delta! Persia! New Zealand! Ecuador! Argentina! N. Ame- 

 rica (Michigan!) 



A. veneta is well characterized by its elongated central nodule and distant median striae. 

 The connecting zone is variable in its structure. Frequently the divisions are difficult to see, 

 sometimes they are clear and distinctly transversely striate. 



4. A. Szaboi Pant. (1889). — Frustule in outline orbicular with slightly rostrate ends. 

 L. 0,035; B. 0,028 mm. Zone with numerous divisions, about 5 in 0,oi mm., transversely striate; 

 strise 19 in 0,oi mm. V. broad, lunate, with straight or slightly concave ventral margin and 

 subrostrate obtuse ends, curved inwards L. 0,o3 to 0,o6; B. 0,oi3 mm. Median line almost 

 straight, approximate to the ventral margin. Axial area distinct, frequently dUated in the middle 

 on the dorsal side of the central nodule. Strise on the dorsal side 13 to 17 in 0,oi mm. coarsely 

 punctate. Striee on the ventral side 17 in 0,oi mm. short, marginal. — Pant. II p. 39 PI. II 

 f. 20. A. hevesensi.i Pant. II p. 37 PI. II f. 32, PL III f. 46, PI. IV f. 68. A. Wiesneri Pant. H 

 p. 40 PI. Ill f. 45. A. arcuata Pant, n p. 35 PI. IV f. 70. A. minuta Pant. 11 p. 38 PI. I f. 16. 

 A. coffeiformis var. fossilis Pant. II PI. IV f. 69? 



Brackish water: Hungary, fossil (Szardoc!) 



I have united all the above named species of Pantocsbk, being unable to find in the figures 

 or descriptions any difi'erence of importance. They diff'er only ir. size and, slightly, in the number 

 of strise. This species seems to me to be nearest akin to A. veneta, from which it is however 

 quite distinct. 



5. A. Normani Rabh. (1864). — Frustule elliptical, truncate, frequently with somewhat 

 rostrate ends. L. 0,02 to 0,035; B. 0,oi mm. Connecting zone with numerous, frequently indistinct, 

 divisions (about 12 in 0,oi mm.). V. narrow, lunate, with more or less distinctly capitate ends 

 curved inwards. L. 0,22 to 0,o3; B. 0,004 to 0,oo5 mm. Central nodule strong. Median line at 

 some distance from the ventral margin. Strise on the dorsal side 17 in 0,oi mm. Ventral side 

 structureless. — F. E. Alg. p. 88. V. H. Syn. p. 56. V. H. T. N:o 5. A. humicola Grun. A. S. 

 Atl. XXVI f- 90 to 92 (1875). V. H. Syn. PI. I f. 12. A. humic. var. javanica Grun. A. S. Atl. 

 XXVI f. 89. A. humic. var. calderiorum Grun. in CI. M. D. N:o 191. 



Moist earth: Sweden, Upsala! Belgium! Harz (Atl.), Java (Atl.). 



6. A. buUata Cl. — Frustule subrectangular, truncate, centrally contracted on the ventral 

 side with a gibbosity in the sinus. L. 0,025 to 0,055; B. 0,oi to 0,oi2 mm. Zone with about 

 5 divisions in 0,oi mm. obscurely striate. V. with protracted, subcapitate and somewhat incurved 

 ends. Median line at some distance from the ventral margin. Dorsal side obscurely striate; strise 

 about 17 in 0,oi mm. Ventral side not striate. 



Marine: Macassar Straits! 



7. A. commutata Grun. (1880). — Frustule elongated, linear elliptical, with rounded ends. 

 L. 0,05 to 0,085; B. 0,02 to 0,026 mm. Zone with longitudinal rows (5 in 0,oi mm.) of short, fine 

 striae (29 in 0,oi mm.). V. linear, with rostrate, incurved ends. Median line biarcuate. Axial 

 area moderately large on the dorsal side. Ventral side without strise or with a row of short, 

 marginal strise, about 15 in 0,oi mm. Dorsal side with 9 to 10 strise in 0,oi mm. — V. H. Syn. 

 p. 58 PI. I f. 14. A. affinis W. Sm. B. D. I p. 19 PI. II f. 27. H. L. Sm. Typ. N:o 28. A.pellu- 

 cida A. S. Atl. XXVII f. 11? 36, 37. A. rohusta A. S. Atl. XXVII f. 38. A. rohusta var. minor 

 Dannf. D. of Baltic p. 20 PI. I f. 7. 



Brackish water: Baltic! Mansfelder See! England! Belgium! France! 



