• >_> (('Nil. SS ii:«'\i i,ii NATIONAL HKRBARIUM. 



• uiih a broad, central, I mgitudinal, hyalii • litly wider 



the center of the valve; and distant beads, two to (our 01 



; iln- median line, until near the ends, then becoming concentric 



to the points of the api< 



ili of valve, 0.08 nun., width of valve, 0.018 mm. Rows 1 I beading on under 

 valve, 88 in o.l mm.; on upper valve, 56 in 0.1 mm. 

 Type in the 1 S National Museum, Ko. 590143, from station 3635H Bering S 



1 1 fathoms, bottom • nd. 



The nearest approach to the above 1- Achnanthidium Achnanth 

 but the differ* • reater than the resemblance. The beading on the under 



ventral aide of I leve's species 1- 68 in <>.l nun. with a valval length of 0.048 nun.. 

 whereas in mine it is ss in «». 1 mm. with a vulval length of 0.08 mm. ; in other v 

 it is > ery much finer on a valve about twice as large .1- the proport ion between size of 

 valve and striatum in Cleve's species would be in my specimen 11 instead of ss in i>. I 

 nun. Bui what Bhows that this is nol a very finely marked though large specimen of 

 the above is that the valves do not taper, but have blunt, rounded ends; the markings 

 are strictly transverse excepl toward the apices; the stauros is < 1 1 1 i 1 « ■ broad ; the raphe 

 ded and bifurcates near the ends; there is a broad, hyaline line on either Bide of 

 the raphe; ;i distinctly marked rim of uniform breadth runs around the entire \al\<-. 



COCCONEIS Ehrenb. 



onei* Ehrenb. fnfus. 193. pi. 14./. 8 9, pi. 21. /". //. L* 



Grun. Verh. Zool. Bot. Ges. Wien 12: 129. L862. Penzl,Reise Movant 

 Bot. 1: L0. 1870. 

 Orthoneis Grun. in part, in Fenzl, R-eise Novara Bot. 1: 9 1". i s 7i>. 

 AnorthoneU Grun. in Penzl, Eleise Novara Bot. 1: 9 L0. 1870. 

 ( irunow breaks up Ehrenberg's genus by emending its scope and creating the above 

 three new genera. I do not find any advantage in this arrangement. Ehrenberg's 

 generic concept 1- a well-marked and precise one; its members arc in clear con- 

 trast with other diatoms by their Bolitary growth attached by the inferior, raphe- 

 bearing valve, by the concavo-convex Bhape of the frustules, by the general, perhaps 

 universal, dissimilarity of the infei ior and superior valves, and by their uniform oval 

 or Buboval contour. However useful Grunow's distinctions may be for Biibgeneric 

 division, it seems to me I est i<> leave these forms in the compact and satisfactory genus 

 that Ehrenberg constructed tor them. This view seems to prevail with most author-. 

 Cocconeisa antiqua Temp. & Brun. Mem. Soc. Phys. et Hist. Nat. Geneva 30": 32, 

 pi. 8. /'. 5. 1889. Schmidt, Atlas pi. 191./. 50, 52. 1877. 

 Cocconeis trachytica Pant. Beitr. Bacill. Qng. 3: pi. 42./ 582. L893. 

 The form from -tat ion 3604B is identical with Schmidt '.- figures above. It is, how- 

 ever, wide of the type, and 1 assign this name to it with some doubt. More typical 

 specimens occur at Btation 1029H, together with a variety which lacks the curved 

 hyaline hand- midway between the raphe and the Bides. 



Found at stations 3604H, I029H, Bering Sea. 

 Cocconeis baldjikiana Grun.; Van Beur. type no. : >i<>. Schmidt. Atlas pi. 190. 

 10. L894. 

 Cocconeis scutellum Ehrenb.; Grun, Bot. Centralblatt 33:324. 1888. Cleve in 



Schmidt Atlas pi. 190./ : 10. 1877. 

 I agree with Schmidt in the above citation that Grunow's union of this beautiful 

 and vigorous form with C. 8cutellum Ehrenb. is inadvisable. Even Smith.- too 

 strongly marked figure 6 of the latter lacks the beautiful broadening of the marking! 



a Bih. Sv. Vet. Akad. Bandl. 1 : 25. pi. ../ 1873. 

 MY. Smith, Synop. Brit. Diat. 2: pi ■;./. 84. i s; >*''- 



