Protistplnnkton. 



Ill this way tlio dnilcs continue inw.nils. until their arc :} 

 iatt'ial. :! transverse and -i sairittal imes. In tiie ijorsal view ithe 

 lateral section' there will, therefore, be seen 2 coiieentrie, some- 

 what oval, inner shells eneircleil by a broail cross ginllc and a 

 lateral airdle, which is still broader and more or less completely 

 developed and is seen in profile (f. -12 a, b.) In the lateral view 

 (on the sairittal section) will also be seen two inner shells, both 

 iihloni^-rectaiiL'iiiar. Thi' iiiiieriiinst diie is coniiectrd with the 

 next one. by a more or less clearly disceiiiihie i;inlle, the inner 

 lateral jrirdle. Inside the innennost one, there are traces of yet 

 another smaller one. Outside the outermost one, will be seen the 

 more or less complete broad lateral girdle (f. 42, e. f.) In the 

 apical view (the transverse section) may also be seen two inner 

 shells, almost square with curved sides. The middle one is joined 

 to the outer transverse girdle by another girdle which is not very 

 broad — the sagittal girdle. Round the figure the transverse girdle 

 is seen in profile (f. 4:2 e. d; the eiidiiieces of tiie lateral girdle 

 are here undeveloped). 



It must not be understood that the ghdlcs are developed from 

 the outside inwards, in the order in which I have described them. 

 (.Ml the contrary, it is probable here too that the formation of the 

 skeleton is centrifugal, the innermost portion, perhaps, excepted. 



The most important ditference between the structure of this 

 species and that of Tetraiiifh}niim Hcic. is that in this latter genus 

 (according to Hck.) 3 separate trizonal shells are developed one 

 outside the other. In the form here described, on the other hand, 

 it will be more or less arbitrary to distinguish between several shells 

 on account of the connecting belts which in themselves constitute 

 a clear structural plan. 



There is, too. a number of radial spines, which are especially 

 detinite and strongly developed in two diagonal planes, and here 

 form 8 protruding spines at the coniei's, as in Ociopijle ocfosti/le 

 and several similar forms. 



There are, also others, apparently irregularly scattered, which 

 support the outside lateral girdle. 



Finally, a rather large number of byspincs occur on the outer 

 part of the shell, short, needle shaped and with a broader base. 



The pores are uneven, somewhat larger on the outer lateral 

 girdle, roundish, oblong and polygonal ; with strong separating walls, 

 \\lien they are fully developed. On the transverse girdle, the pores 

 are smaller, roundish, very uneven, with wide separating walls. 



The girdles are all rather irregularly developed, not symmetri- 

 ( il. Neither are the radial spines symmetrically placed. 



As already mentioned, it cannot be seen from Haeckel's de- 

 Miiption, what is the actual structure of the genus Phm-ticium. I 

 have, therefore, refrained from proposing any new name, until 

 Haeckel's species Phortmitm pi/hinnm is more clearly defined. 



To the form here described belong also the majority of Octo- 

 j';/lr octosti/Je HcK. /'. mi)ior Joeg. 1. c. p. 64. These foi'ms are 

 Ir-s developed than Tetrapylonium Clcrei, but seem, generally speak- 

 iiiL'. to belong to the same species. To the same forms too, the 

 I'li'Jiik-iinii jiijloiiiioii illustrated by IIaeckel would appear to 



lirlollg. 



It is. however, quite likely, that at least two species are con- 



it ahvavs in small 



luuibei 



deep 



Rather frequent, 

 water samples. 



Disirilnif'ion : Not unfreipient on the west coast of Norway, also 

 in deep water samples. Cleve has found it in samples from deep 



water from the sea west and south of Spitzberiren, as well as in 

 surface samples from the American side of the North Atlantic. 

 Also known from a few places in the Norwegian Ocean. 



IIaeckel designates Fliurticita» p;/lonium as cosmopolitaii 

 (Mediterranean. Atlnntif. I'ficili.- etc ..surface and in various 

 de|)ths".) 



VII A. «. IJllioliilH. lIcK. 



■jHr«-OM|>ira minor (.hiw..) 



Liflicliun miliar .Iiihg. J^. <)1, p. (Jo, p|. .5, f. 24. 



This species has a very dirterent appearance, according to tin- 

 position in which it is seen. 



In one position it has an appearance corresponding to tin; illu- 

 stration referred to, and which caused me to consider it as a Li- 

 thelius with a double spiral. 



On being rolled under the microscope it has, in another posi- 

 tion, the appearance of 3 distinct (concentric) shells, one outside 

 the other, the innermost being somewhat oblong, the other two 

 rounder. 



In this last position, an iudefinite contour of an inner, smaller 

 shell is seen in the innermost one. 



From which one may probably conclude that the innermost of 

 the three shells is double, Larnucilla-shnped or trizonal fac- 

 cording to Haeckel's designations). I have not, however, succeeded 

 in seeing this clearly. 



Form this shell there extends, on both sides, a transverse 

 girdle, which winds itself into a spn-al about the largest axis of 

 the inner shell, the longitudinal or principal axis (after Haeckel). 

 These two spirals give rise to the appearance of a LifhÆus with 

 a double spiral, when looked at from above (transverse section, after 

 Haeckel apical view). 



In a certain, a little oblique, position one gets again a more or 

 less indefinite impression of a single spiral. 



In each spiral there is only a little more than one tuin. 



Pores somewhat uneven, not large. 



Numerous, long, narrow, needleshaped radial spines. (Cfr. also 



JORGENSEN 1. C. 1. 



One of the most frequent radiolaria in the north, sometimes 

 also rather numerous, especially in ocean samples. 



Distribution: Also rather frequent on the west coast. Known 

 too from a few places in the Norwegian Ocean, where it occurs 

 together with southern forms. 



Note. \Miat is in one instance in the tables entered as Lithelins 

 spiralis Hck. is very uncertain, and it is probably only a form of 

 LurcospirK minw, which, as already mentioned, in certain positions 

 gives the appearance of a single spiral. The same is the case with 

 regard to L. spiralis .Tiikg. L. 91, p. <w;. 



VII A. 7. Strebloiiida Hck. 



Ktrt'blacuntliu circumtexta (Joni;.) 

 (PL XI and XIl, f. 4li). 



Sorularciis circumtextus Jorg. L. 91, p. 65. 



This is also a very difficult form to define, and I have not yet 

 succeeded in getting a clear insight into its structure. It can, how- 

 ever, not belong to the genus Sorolarcus Hck., as I at first thought. 



IH 



