4 P. T. CLEVE, ON DIATOMS FliOil TIIE ARCTIC SEA. 



1. Hyalodiscus stelliger Bail. (Smiths. Contr. VII Obs. p. 

 10. 1855. Coscinodiscus punctulatus Greg. D. of Clyde. pag_ 

 500, Pl. X, fig. 46? Py.ndicula Adriatica? Cl. Diat from 

 Spetsb. p. 662). Valve convex and covered by small and 

 dense cellules, arranged in curved lines, crossing each other.. 

 Celliiles about 30 in 0,0 2 5 m.m. The cellules are not so dense 

 as in specimens from California, on which I have couuted 38- 

 cellules in 0, 02 5 m.m. Specimens from Magellhaens Strait have 

 25 cellules in 0, 02 5 m.m. and according to Grunow the cel- 

 lules of H. stelliger are much more dense viz: 40 — 45 in 0, 01". 



This species is very common in the arctic sea. Spetshergen:. 

 Schoal Point, Hinlopen Strait, Wijde Bay, Röde Bay, Waijgats- 

 Ids., Brandwyns Bay; depth 10 — 30 fathoms. Greenland and 

 Finmarken. The H. stelliger is found also near Kamtchatka 

 (Grun), California, Chile (Grun) jMagellhaens Strait (Cl), Florida 

 (Bail), Cape of Good Hope (Grun), St. Pauls Id (Grun). If 

 Coscin. punctulatus Greg be the same as H. stelliger it 

 occurs also on the coast of Scotland. 



2. Hyalodiscus subtilis Bail. (Smiths. Contrib. VII Obs. 

 pag. 10, fig. 12, 1855. Craspedodiscus FrankUni Ehb. M. GeoL 

 Pl. XXXV a. 23 fig. 6. Melosira FrankUni Clev. Öfvers. 

 K. Vet. Akad. Förh. 1868 pag. 216). 



This species is also very common in the arctic sea and 

 has been found in numerous samples from Spetshergen: Brand- 

 wyns Bay, Waijgats Ids. etc. Greenland very common. Fin- 

 mar^ken Grötsund somewhat rare. 



Hyal. subtilis is widely distributed and obser\^ed in the 

 following localities: 



Kamtchatka (Grun), California (Cl), Chile (Grun) Patagon.. 

 Guano (Janich), Australia (Cl and Hendry), Honduras (Rab.. 

 and Janich), Xova Scotia (Bail). 



?3. Hyalodiscus maculatus (Sm) Cl. (Podosira maculata Sm. 

 Br. Diat. II pag. 54 Pl. XLIX fig. 328). This species which 

 agrees in its sculpture very nearly wåth Hyal. stelliger and 

 with H. subtilis in its central irregular sjDot, has been obser- 

 ved only in the deposit from Kings Bay in Spetsbergen and is 

 for that reason doubtful as an arctic species. This diatom is 

 also found on the coasts of Great Britain, France, Sweden 

 and Germany. I also observed it in materials from the West- 

 Indies and from Costa Eica. 



