i. Jørgensen. 



C. subbulliens n. sp. 



(Pl. vr, fig. 2.) 



Form: — The valve is clearly convex, with an evenly rising 

 marginal zone. Seen from the side, its contour is almost straight 

 with an angle of between 30 and 40°. The central part (to V, or 

 'A of the radius) almost flat or often somewhat depressed. 



Margin : — Clearly defined, broad and sharp, with coarse stripes. 



Structure: — No central space. Generally either without or 

 only with a slight indication of central rosette, consisting of a few 

 larger polygons, without any regular arrangement in rosette shape. 

 On larger specimens, a more distinct rosette with five larger areoles, 

 hanng their narrower ends directed inwards. 



The majority of the areoles increase slowly in size from the 

 centre (outside the few larger central areoles) to Vs — Vo of the 

 radius where they are largest. From here they suddenly become 

 much smaller (although not very small) and are about of equal 

 size right out to the margin. All over the valve — both in the central 

 part and further out — smaller areoles are strewn between the 

 larger ones, and this often strongly I'esembles the structui'e of C. 

 Jnilliens A. Schm. (hence its name). 



Markings polygonal, tMck walled with very plain „papillæ". 

 (Structure irregularly dichotomously radiate: From the centre 

 numerous radii diverge, generally 2 or more being parallel. In the 

 spaces between such rows of rays, new radii spring out, the first 

 areole often being small. Where the cells have reached their greatest 

 breadth, two new rows often spring out. Here and there, close to 

 the margin, short new rows again fill up the intermediate spaces. 



Skc: — Rather small, considerably smaller than C. centralis, 

 aViout equal to a little C', radiatuf in size. Diameter usually .50 — 

 l(K) n. 



The living cell is of medium heiglit, higher tlian in C. rrt'Hatus 

 and generally much lower than in C. ^■oncinnus. 



The central areoles, when they are found to be well developed, 

 ai-e 3x4 ]).. 



The areoles outside the central rose 

 3,5 |). broad, 2—2,5 \>. at the border, 

 smaller areoles, 1,5^2 ]).. 



At the border 5'/2— 6 stripes on 10 

 same number of areoles). The margin 

 being nearly cubic-cylindrical). 



This species, which, judging from my experience, is well de- 

 fined and easily recognisable, resembles the C. radiatus most nearly, 

 and may, unless great care be taken, be confused \\ith it; tlio con- 

 vex valve and the absence of the very small areoles neai- tlic mar- 

 gin will, however, at once show the decided difference. 



Tills species is also Grax's C. ocuIus iridis after his inter- 

 pretation of this species in Plankton des norwegischen Nordmeeres 

 (L. 70, p. 168), as I have had an opportunity of being convinced 

 of, on comparing some of his plankton samples. 



Cleve's C. oculus iridis appears to consist in a great measure of 

 this species, judging from his plankton lists, but as he — as above 

 mentioned — refers to Grunow's figure of C. asteromphcdiis var. 

 hijhr'tdK, which is hardly specifically diff'crent from what Gkunow 

 considers to be C. centralix Ehkb., it seems to me that Cleve's 

 species must consist of forms which are specifically different from 

 each other. 



Grunow's C. centralis, which he considers a variety of C. asterom- 

 phalus, is not so well characterized as Rattray's C. centralis, but 



4 on 10 1)., the 

 Here and there 



largest 

 much 



|). (coiresponding to the 

 3 'J. broad (the areoles 



must, I think, be reckoned as belonging to that species. Grunow's 

 C. asteivmphalus also belongs to it, answering as it does quite well 

 to the coarser forms of C. centralis (Rattr.) having, as a rule, in- 

 distinct marginal apiculi. Grunow expressly mentions (L. 83, p. 

 27) the convexity, while C. sudbidliens has a gradually descending 

 marginal zone and therefore is less noticeably convex towards the 

 margin. 



Ostenfeld, again, considers C. ucidus iridis not to be specific- 

 ally different from C. radiatus and therefore does not enter it se- 

 parately from the Faeroe Islands (L. 116, p. 566). 



Other authors on plankton have, in their lists, given very various 

 names from districts where, at any rate, partly the same species 

 are hkely to occur, from which it will be seen that there is a 

 considerable difference of opinion with regard to C. oculus iridis, 

 C. aster omphalus, C. radiatus and C. concinnus (C. centralis is not 

 generally mentioned). 



As the species here mentioned as C. subbulliens does not cor- 

 respond well to C. oculus iridis, as one has reason to believe this 

 species was originally looked upon — large, with large central rosette 

 and thus differing from C. radiatus — and as there is such a 

 great difference of opinion with regard to the correct meaning of 

 this name, I have thought it best to determine the characteristics 

 of the species, and to use a new name for this form, which is 

 easily recognized. I have not been able, in spite of careful com- 

 parisons, to identify it with certainty with any of the species hithei'to 

 described. Of names which might be taken into consideration, I 

 will particularly mention 6'. heteroporus and C obscurus. The latter, 

 especially, has many points of similarity with my species, but it 

 does not seem possible, however, from the figures which have been 

 given, to consider them as being identical. 



On the other hand, there are certain forms which have been 

 referred to C. radiatus, which surely belono- to my species. I will 

 for instance, specially mention tab. 60, f. 14 in Schmidt's atlas 

 (0. ohversus Rattr.) which fairly well answers to many forms which 

 do not specifically differ from my C. subbulliens. As I, however, 

 principally base the right of specific rank upon the peculiar con- 

 vexity of the valve, (in side view), I cannot, for the sake of perfect 

 clearness, very well use Rattray's name, which represents a spe- 

 cies, which is but little known. 



It is not to be expected that there can be absolute agreement 

 as to the use of Ehrenberg's names C. oculus iridis, C. centrali-^. 

 C. radiatus and many other. But one might perhaps more easily 

 agree as to the meaning of the original name, C', radiatus, which 

 is already by most authors used as I do here, excepting that, to 

 some extent, other species are also occasionally included thei'ein. 

 If the name C. radiatus Ehrb. be retained, there can hardly be 

 any reason for not attaching to it the meaning above mentioned. 

 It is quite anothei" matter, that there are perhaps those who mean 

 that there still are included in this species others, which in the 

 future will have to be culled out. 



Further, there can hardly be different opinions with ivgard to 

 Rattray's C. centralis, unless that some may consider the limits 

 of his species to be too confined, while others may find those of 

 mine to be too wide. At present, it appears by many — as above 

 mentioned — to be looked upon as belonging to C', concinnus 

 W. 8.M., and 1 have previously also been of this opinion. 



On the other hand. I think that C. oculus iriilis must be 

 sacrificed (as a species), while ( '. subbuUivus, which is certainly 



