197 



Border sharply defined, dark, striate. The disc somewliat convex 

 towards the border. 



The spociiiR'ii fcnini! only ilitfci's tVnin SciiMinr's lii^iirc in 

 wantin;:- the ..reutral space". Instead of tins space, wliicli is, iiow- 

 ever. not mentioned liy iiArrnAv 1. c, a laiv' aroolo was present. 



Distrihutioii: I'acilie Ocean, especially in the northern rcgioia 

 (ivaintschatka tSea, ISailey). t'ape Wankarenia (Ci.kvk). 



C. decrescens Uri n. 



mil, p. 28. A. Schmidt All 

 Eatthay 1. c. 1). 77. 



til, figs. 



Perhaps a plai 



Coarse structni 



the i-aitiil decreasin; 



kton foi'ni, occni'rintr with us like ('. siMiiUiens. 

 \ conspicuous ..papillæ". Recognizable through 

 ■ of the areoles outside of 'A radius. 



Hare: Moskenstiouunen r -|-, Stamsund r. Diameter 92 {>. or 

 less; largest areoles somewhat outside of V2 radius, 2 on 10 \>., at 

 the centre smaller, on the bordei' much smaller. J^order broad, 

 sharply defined, striate, with .5 — 1) stiiæ on 10 {>■. Central space 

 generally absent (answering;' to rar. ivph-ta GErx. 1. c), sometimes 

 present. 



Distribution: Fa?i'oe Channel. Franz .losef's Land, .Japan, 

 Macassar Straits, Florida. 



C. radiatiis Khrb. 



Cf. aboYe p. 92. 



Probably deriYed fiom the plankton. 



Rather frequent: Moskeustrommen c, Stamsund r +, Svolvær 

 r, Østnesfiord r, Gaukværo +, Stene r. 

 Distribution : Cosmopolitan. 



A. SCHM. Nor 



var. minor A. Sciim. 

 p. !I4, jl. :3, f. 4. C. (Icvius A. Schm. Atlas, pl. 



Stamsund r, Svolvær r, Gaukværo r, Stene r. 

 var. oculus iridis (Ehub., Eattr.). 



Flat. A conspicuous central rosette and often a small „central 

 space". Areoles largest at or beyond V2 radius, hexagonal, with 

 large „papilla", towards the border rapidly decreasing, at the very 

 margin small. Largest areoles 3 on 10 [>■. 



This form, which answers very well to C'oscinodiscus oculus 

 iridis Ehrb. Mikrogeologie pi. 19. fig. 2, is certainly not specific- 

 ally distinct from C. nuliattts. intermediate foi'ms being rather 

 frequent. 



Moskcnstrouuncn r. Gaukværo r. Occui'i'eil also in other 

 samples. 



C. nodulifer Jan. 

 .Taxisch. ill A. Schmidt Athis, pi. 59, f. 21. 



Flat. A small, but conspicuous nodule near the centre. Are- 

 oles hexagonal, increasing from the centre to 74 radius, here 3 on 

 10 \i; towards the margin rapidly decreasing, at the border 5 — 6 

 on 10 \i. Border shai-ply defined, striate, with 6 — 6 'A striæ on 

 10 11. 



Answers very well to the figure referred to. 



Rai-e: Raftsund +, Brettesues— Skroven r. 



Distribution : This southern species is found near the Balearic 



I Islands and in the warmer regions of tiie Atlantic, Pacific and In- 

 dian Oceans. 



it is very reniarkalile that this species occurs .so far noiHi. 

 It is probalily a plankton form, most likely a fos.sil one. 



Actinoryrlns Eiirh. 



A. alienus (iju n. 

 Grlx. in Van Heurck Synopsis, pi. 12.5, f. 12 (var. arctinisl. 



Very rare: Brettesnes— Skroven r; Stene r. ln structure 

 Coscinodiseus-like, as Grunow states intermediate between C', cur- 

 vatulus and C. radiatus. Central space circular, conspicuous, only 

 with a few irregularly scattered puncta. Numerous fasciculi (over 

 20) with interfascicular radii, which are more or less plainly ziczac 

 bent, especially towards the centre. Towards the margin, the fasci- 

 culi are not separated from each other, but form an even radiately 

 structured marginal part. Very small and incon.spicuous marginal 

 apiculi. Border narrow, indistinctly striate. 



Diameter 61—66 [i.; rows of areoles 1.5 on H) [i.. at the mar- 

 gin closer. Ocellus marginal, evident. 



Di.stribution: Cape Wankarema. Also mentioned from a few 

 places of the North Atlantic and Arctic Seas. 



A. Ehrenhergi Ealfs. 



Cf. above p. 9.5. 



Probably derived from the plankton. 



Not unfrequent: Stamsund r, Svolvær r, Gaukværo r, Stene -f • 



Distribution : Cosmopolitan. 



A. Ralfsii (W. Sm.) Ralfs. 



Cf. above p. 95. 



More frequent in the bottom samples than in the plankton 

 (from which however must not be concluded that it is a bottom 

 form): Stamsund r, Svolvær \--{-. Ostuesfiord r, Gaukva'io r+. 

 Stene r. 



Dist) ibution : Western Europe. Greenland (Gstkfp). War- 

 mer Seas. 



Rattr. Revis. Actiii 



A. sparsus (Greg.) Eattr. 

 1890, p. 170. Eupodiscus sparsus Greg. Trans. Jlicr. 

 Soc. 1857, p. 81, pi., fig. 47. 



The description by Rattray does not answer Avell to the figure 

 referred to. According to this figure, it seems chiefly to ditter from 

 A. Ehrenberfji in being more sparsely granulated towards the cen- 

 tre, so that only the interfascicular radii reach the central space. 

 It is, however, doubtful whether it can really be kept distinct 

 from the preceding species. Also A. moniliformis Ralfs seems to 

 be a species very closely related to .1. Ehrcnlnrgi. 



Specimens which seem to belong lici-c were found in the sample 

 from Gaukværo. r. 



A. crassus V. H. 

 Van Heurck Synopsis p. 215, pi. 124, figs. 6, 8. 



Van Hecrck's figure shows interfasciculate radii, though not 

 so evident as those of A. Ehrenbergi. Smaller and coarser forms 

 of the latter species is puzzlingly similar to A. crassus. It is on 



