FRESH-WATER DIATOMS FROM ICELAND 43 



Hypotheca: Striis media in parte valvae deficientibus , ibique 

 fasciam latam relinquentibus. 



Epitheca: Uno in latere media? partis valvse spalium hyalinum, 

 solere equinse inslar, adest. 



Egilstaftr (E.) B. P., Hornafjordr ;E.} St. 



This small form is hardly identical with Hustedt s Ach. lane, ven- 

 tricosa (cnfr. Hnst. Slid. 64, Tab. II, fig. 321; it seems to me, it should 

 rather be placed close to Ach. lane, freroensis. 



Achnanthes Peragalli Brim & Herib. Cl. Syn. II, 192. 0sl. D. D.. 

 Tab. IV, fig. 85. 



Apavatn (S.) A. F., ilfjolsvatn (S.) A. F. 

 Area: Eur. 



Achnanthes rhyncocephala A. Cl. A. Cl. Finl., 43, Tab. IV, fig. 85. 



Husavik (N.) B. P., Grimsa (E.) B. P. 

 Area : Eur. 



Kalyptoraphideae 



Eschatoraphideae 



Surirella Turpin 1827. V. H. Trt., 368. 



Surlrella asymmetrica sp. nov., Tab. nost. IV, fig. 63. 



Long: 40 /<, lat: 10 /. 



Valva elliptice-lanceolata, margine una recta, altera autem con- 

 vexa. Area apicali angusta. Canaliculis in margine recta omnino 14, 

 in margine convexa omnino 7. 



In a flowing off from Geysir (S.W.) A. F. 



*Surirella biseriata Breb. V. H. Trt., 369, Tab. XII, fig. 575. 



34 samples (S. 6, S.W. 8, N.W.I, N. 7, E. 12). Hot springs. 

 Area: Eur., Af., As., Am. 



Surirella Engleri O. M. f. angustior. O. M. Nyassa, 28, Tab. 1, fig. 5. 

 A. S. Atl. CCXLV, fig. 14. 



Laugavatn (S.) B^P. MoSruvellir (S.W.) B. P. 

 Area: Af. 



Surirella granulata 0st. var. elliptica var. nov., Tab. nost. IV, fig. 64. 

 Long: 72 /<, lat: 20 //, canalic. 2,7 in 10 u. 



Valva elliptica, irregulariter punctata, area apicali angustissima. 

 Reykjavik (S.W.) C. H. O. 



This form answers in even 7 respect, except by the exterior contour, 

 to Sur. granulata 0st. in Ost. Koss. 91, Tab. II. fig. 17. 



