194 p. T. CLEVE, SYNOPSIS OF THE NAVICULOID DIATOMS. 



according to Lagst. W. Sm. B. D. U PL XXXVII f. 802. V. H. Syn. p. 129 PI. XXVI f. 21 to 

 24. A. multiartimlaia Ag. Consp. p. 59 (1832). A. rapnisis KiJTZ. Bac. p. 76 PL XXI f. I (1844). 

 AchnantJiidium arcHcnm Cl. D. Arctic Sea p. 25 PL IV f. 2'2 (1873). Arhn. Loczjji Pant. II p. 57 

 PL XII f. 217 (1889). 



Brackish and marine: Finmark! Coasts of Britain (Sm.), North Sea! Baltic! Caspian Sea 

 (drnn.), Mediterranean Sea! Amsterdam Island (Grun.). 



Vai". seriafa Ag. (1827). — Frustnles concatenated into Diatoma-like series. Valves elongated, 

 narrow, freqnently broader at one end than at the other. — A. seriata Ag. Bot. Zeitung 1827. 

 Consp. p. (iO. Cijmhofiira Agardhii KtJTZ. Bac. p. 77 PL XX f. 3 (1844). A. scr. rar.? cuneata 

 GrRUN. A. L). p. 19. A. suhsessHis rar. enervis Petit Mem. de la Soc. de Cherb. p. 207 PL XXIII 

 PL III L 2? 



Marine: Adriatic (Klitz), Java! Labuan! Pacific Ocean (Grriin.). 



Var. ungustata Grev. (1859). — Elongated, narrow. L. 0,o7 to 0,15; B. 0,o()r) to 0,oi mm. 

 Striai 10 to 15 in 0,oi mm. — A. angiisfatd Grev. M. J. VII p. 1(53 PL VIII f. 9. A. pennafn 

 Cl. Vega p. 504 PL XXXV f. 2. 



Marine: Californian gnano ((4 rev.), Ceylon! 



Greville figiu'es two coherent frustnles in the zonal view, for which reason the identifi- 

 catation with A. pennata Cl., the fignre of which represents a lower valve, is somewhat doubtful. 



Var.? penncefonnis Grev. (1805). — Frustule biarcnate, long and narrov\^. Lower valve 

 linear obtuse. L. 0, i.'i; B. O.oi mm. Strict; parallel, 12 in 0,oi mm. punctate, puncta 13 in 0,01 

 nun. — Achnanfhes penncef. Grev. T. Bot. Soc. Edinb. Vol. VIII p. 438 PL VI f. 11 to 13. 



Marine: Sandwich Islands! 



Var. indica Brun (1893). — Centrally constricted, with cuneate ends. L. 0,()r, to 0,07 f); 

 B. 0,02 mm. Strict; and puncta 8 to 9 in O.oi mm. — Arlntnnthes nulica Brun Diatomiste I 

 p. 173 PL XXIV f. 14. 



Marine: Rodriguez (Brun). 



A. hrevipcs is an exceedingly variable species, on the varieties of which a great number of 

 »new species', usually imperfectly described and figured, has been founded. The characteristics, 

 by which these reputed species difter, are such trifling ones as the shape of the valve, the size of 

 the stipes, the excentricity of the axial area of the upper valve, etc. But as all these characteri- 

 stics are very variable, I am unable to separate as species the above named varieties. A. iiiflata, 

 A. crenulata and A. coarctata. are so nearly allied to A. hrevipes that it is difiicult to state any 

 stable characteristics for their distinction. Achn. parallela Castr. (Voy. Challenger p. 41 PL XIX 

 f. 11) and A. hcrfjnchnsis Castr. (1. c. PL XX f. 41) would seem to belong to the varieties of 

 A. hrevipes, were not the area of the upper valves represented as central, and the strije of the 

 latter so fine. 



8. ('. perpiisilla Pant. (1889). — V. broadly lanceolate. L. O.oif); B. 0,oo8 mm. Lower V. 

 with narrow axial area. Central area a narrow transverse fascia, reaching to the margin. Median 

 line straight. Strite 17,5 in 0,oi mm. punctate, slightly radiate throtighout. Upper V.? — 

 Pant. II p. 58 PL IV f. 73. 



Marine: Hungary, fossil (Pant.). 



A small form, unknown to me, resembling a small variety of Arlnianflu's s-iihsfssilis. 



9. A. aggliitiiiiltii Gktjn. (1880). — V. nari'ow, lanceolate. L. 0,022 to 0,028; B. 0,004 to 

 0,00.'-, mm. Upper V. with L! ])unctatp strije in U,oi mm. Lower V. with 15 punctate striiK in 

 0,01 mm. — A. D. p. 19. 



Marine: Triest. 



This, to me unknown form, resembles according to Grunow A. suhsessilis, but occui's attached 

 by the iowt'i' valve to seaweeds, not on gelatinous stalks as A. suhsessilis. 



