BIHANG TILL K. SV. VET.-AKAU. HANDL. BAND 1. N:0 13. 25 



126. Rhabdonema minutum (Kg) Sm (Syn. II, pag. 35, 

 Pl. XXXVIII, lig. 306). Tolerably common in the arctic sea 

 Spetsbej'gen many localities. Greenland. Finmarken. 



This species occurs on the coasts of Sweden and Great 

 Britain, has been found also at great depths in the Baltic sea, 

 but has not been observed either in the Mediterranean or in 

 the tropical seas. It has been found by Mr. Grunow in samples 

 from the Cape of Good Hope. 



127. Rhabdonema Adriaticum (Kg) Sm (Syn. II, pag. 35, 

 Pl. XXXYIII, fig. 305 d & b') very rare. Spetsbergen Kings 

 Bay (160 faths). Finmarken Grötsund. Only some very few 

 frustules of this, otherwise very common species, have been 

 found in the arctic sea. Rh. Adriaticum occurs on the coasts of 

 Sweden and Great Britain, in the Mediteranean and Red seas, 

 on the eastern coasts of North America, in West Indies, Brasil 

 (Gruu) Cape of Good Hope (Grun). St. Pauls Id. and Mau- 

 ritius (Grun) Honolulu (Cl). 



? 128. Achnanthidium brevipes (Ag) Heib {Achnantes bre- 

 vipes Sm Syn. II, pag. 27, Pl. XXXVII, fig. 301 and 301 /?). 

 Spetsbei'gen Schoal Point. A somewhat doubtful arctic spe- 

 cies, as it has not been found in any sample examiued by 

 me after the year 1867. 



129. Achnanthidium arcticum Cl N. Sp. S.A^. linear ob- 

 long, apices rounded, somewhat constricted in the middle. 

 The convex valve with coarse strise, composed of large and 

 distinct puncta (striae about 13 in 0,0 2 5 m.m.). Concave valve 

 with more numerous strise (about 17 in 0,o 2 5 m.m.), composed 

 of more numerous puncta in the middle with a distinct raphe 

 and with a broad stauros. Connecting membrane with seve- 

 ral rows of fine puncta. 



Length 0,048 m.m. Height 0,0 2 4 m.m^Breadth 0,oi7 m.m. 

 Spetsbergen, Greenland, Finmarken. 

 PL IV, fig. 22 a¥.\. b S. \. 



130. Achnanthidium Groealandicum Cl. N. Sp. S. V. linear, 

 Convex valve without any distinct median line and central 

 nodule; stria? coarse, composed of some few, distinct, large 

 puncta. Concave valve with distinct median line and with a 



