KONCL. SV. VET. AKADRMIENS IIANDI.INGAK. HAND 27. N:<» 3. 18') 



Jtriae distinctly iiunctate A. nnigellanica Pet. 



— not distinctly punctate 4. 



. Axial area distinct A. angusta Vl. 



not distinct 5. 



'ormis Ci,. 

 tuminosa Pant. 



{ 



(. j Median line straight A. cymbif 



' ' \ — — slightly hiarcuate A. hitmnin< 



1. A. angusta (Greg. 1857) Cl. — V. narrow, semilanceolate, acute or .subacute. L. 0,04 to 

 0,1,3; B. (),()().^) to 0,018 mm. Median line straight, parallel and approximate to the ventral mai'g-in. 

 Axial area distinct and frequently moderately broad on the dorsal side, indistinct or small 011 

 the ventral side. Stria; 7 to 17 in 0,oi mm., not distinctly punctate. Both the dor.^al and the 

 ventral sides of the valve are striate. 



This species comprises a number of forms. 



Var. fijpica Cl. — B. of the frustule (»,o]. L. of the valve O.o.^) to (),().-)r, ; B. 0,()o.'-) to 

 0,o()7 mm. Stria; 17 to 18 in 0,oi mm. — A. an(/ttsfa Greg. I), of Clyde p. r)10 PI. XTI f. G(\. 



A. amjHSfu var. ffraciJcnta Grun. A. S. Atl. XXV f. 15. A. Eulcnstcinii var. fossilis Pant. 1889 11 

 p. -M) PI. I f. k PI. Ill f. 49. Cymhella marina Castr. Cliall. Exp. D. ]). .31. PI. XXVII f. 13? 



Marine: Scotland (Greg.), Spitsbergen! Sea of Kara! Quincy, Massachusetts! Czekehaza, 

 Hungary (fossil)! Jamaica (Grove Coll.). 



The figure of A. aiKjusta. in Diat. of the Clyde is not sufficient for identification without 

 original specimens, but as in the description is stated that it has 17 to 18 strite in 0,oi mm. I 

 think that A. ancju^ita Greg, may denote this form. A. Euloisfeinii var. fossilis is described as 

 having 20 to 22,5 strise in 0,01 mm. I found 18 only in specimens from Czekehaza. Cymhella 

 marina Castr. may be this or another form of A. angusta, it is impossible to decide which from 

 the figure and the description. 



Var. ohlongella Grun. (1878). — Frustule in breadth 0,ou8 to 0,oi3. V. in L. 0,0.32 to 0,o68; 



B. 0,006 to 0,01 mm. Striffi 14 to 1;") in 0,oi mm. — A. ohlongella Grun. Casp. Sea D. p. 7 PI. IV 

 f. 20. A. exigua Greg. D. of Clyde p. 514 PI. IV f. 75? A. angusta var. arctica Grun. A. D. 

 p. 24 PI. I f. 9 (1880). A. lanceolata var. minor Cl. Vega p. 462 (1883). 



Marine and brackish: Sweden (Bohuslan)! Firth of Tay! East cape! Behrings Island! Ba- 

 learic Islands! Caspian Sea (Grun.), Campeachy Bay! Pensacola! Honolulu! 



A. exigua Greg, may be this form although the stria' are stated to be 11 in 0,oi mm., 

 but it is impossible to decide without original specimens. 



Var. Eulensteinii Grun. (1875). — L. of the valve 0,o8 to 0,121; B. 0,oi6 to 0,02 mm. Striae 

 11 to 12 in 0,01 mm. somewhat closer on the ventral side, or aboiit 14 in 0,oi mm. — A. Eulen- 

 steinii A. S. Atl. XXV f. 1 to 3; XL f. 35 to 37. 



Marine: China! Japan! Govans Bay; Raised March; Leton Bank (Atl.), Cape May! 



Var. diducta A. S. (1875). — V. gibbous in the middle. L. 0,082; B. 0,oir) mm. Dorsal 

 strife 10 to 11 in 0,oi mm. — A. did. A. S. Atl. XXV f. 13. A. egmhelloides var. latior Grun. 

 Atl. XXV f. «. 



Marine: Java, Japan (Atl.). 



Var. rentricosa Greg. (1857). — V. in L. 0,0.'-);) to 0,i3; B. 0,oi3 to 0,oi8 mm. Dorsal .striae 

 8 to 9 in 0,01 mm., ventral somewhat closer. — A. mitrirosa Greg. D. of Clyde p. 511 PI. XII 

 f. ()8. A. lanceolata Cl. D. from Spitsb. p. 667 PI. XXIII f. 2 (1864). Cymhella erioj)hila Castr. 

 Chall. Exp. D. p. 21 PL XXVII f. 5 1886 (stria; distinctly punctate)? Cymhella marina Pant. Ill 

 PI. XIX f. 274? 



Marine: Greenland! Spitsbergen! Sea of Kara! Finmark! Coasts of Scotland, Norway and 

 Bohu.slan! Adriatic! Bab el Mandeb! Monterey (Atl. XXV f. 6). 



The fig. in Diat. of the fHyde is insufiicient for identification, still I have little doubt that 

 Gregory denotes this form. An intermediate form between V(rr. rentricosa et Var. Eulensteinii 

 is fig. 5 PI XXV in A. S Atl. 



