258 CONTRIBUTIONS PROM THE NATIONAL EERBARITTM. 



i Schmidt, Atlas pi i s > Van Heur. Synop. pi. ISO, 



881. I leve A Mall, type no. I 



fallai Schum. Schrift. Phys. Okon. Geaell. KonigBb. 8: <;_'. pi, 

 1867 cf. < astr. Rep. Voj . Chall. Bot. 2: 166. pi L88( 



raj includes under the above category several i which are omitted 



hen 



Found at Btatione 2807, 3604, 2835, Galapagoe Islands, ofl Lower California and 

 Bering 3 



Coscinodiscus robustus Gn \ Trans. Mi< r. Soc. Lond. ti. B. 14: 3. pi, I./. 8 



Ifoeb. Diat.-taf . pi. 70./. S 1890. Jan. Diat.Gaz. Enped.pl. 4>f. 10 11. S4-hnn.lt. 

 Atlas pi. 62. ./'. 16, 11 (not /. / 6 , 1878. Grun. Denkschr. Akad. Wien 48'-': 72. 

 1884. Ratt. P*oc. Roy. Soc. Edinb. 16:511. L889. DeToni, Syll. A1 f #■ L243. 

 1894. I'i \n XI. VIII. 1 



■v.vr'/N stilnihitns Grun.; Schmidt, Atlas pi. 65./ •. l sv l. 

 nodiscus marginatus Ehrenb. var. Grun. Denkschr. Akad. Wien 48 i 

 binkerianus Truan & Witt, Diat. Bayti L3. pZ. S.f. 1. 1888. 

 Greville's figure and it- reproduction cited above by Moebius are, as Rattray points 

 out, Bomewhal Idealized. A variety was found at Btation 3399B corresponding to the 

 one thai Schmidt /( considers doubtful. C. subvelatus Grun. is also a rather too divt r- 

 gent variety, while C. binkerianus Truan d Witt is either a variety with unusually 

 narn>\\ margin or a type form with margin wanting. The confusion between this 

 Bpecies and C. marginatus Ehrenb. has been discussed under that heading. 



Found at stations 3346, 3361H, 3399H, 3604, 3663H, 3693H, 3784, 3785, 4023H, 

 1025H, off Washington, Bering Sea and Okhotsk Sea. 



In Rattray's revision* occurs this paragraph: "In a Santa Monica form, 13 mm. in 

 diameter, discovered by Doctor Rae, the usual Btriated border was surrounded l>y a 

 second more Bharply defined but narrower band, with a slightly convex surface, and 

 bearing delicate striae, 8 to L0 in 0.01 nun. At one place this band is interrupted and 

 Bomewhal more convex on the two sides of tin- break. This gives it the appearance 

 of an elastic Bpring enveloping the valve." Specimens of this structure are not 

 infrequent at Btation 3361H, which is in Bering Sea northwest from Pribilof Islands. 

 At Btation L025H, a little north of the Aleutian Islands, it is decidedly abundant. 

 Nor is such a hand confined to this Bpecies. Brund figures precisely this condition 

 on a Bpecimen of C. crassus Bail. It would be interesting to know the precise 

 physiological signification of this feature, its only occasional presence in the different 

 species implying that it has such signification. Figures of this form and a morpho- 

 logical discussi* i of the interrupted diatom girdle have been published by Palmer A 

 keilcy.' The form found at Btation 4025B is represented in the accompanying 

 figure. 



Coscinodiscus simbirskianus Grun. Denkschr. Akad. Wien 48':^]. 1884. Schmidt, 



Atlas pi IIS. f. 11 12. L888. Ratt. Proc. Roy. Soc. Edinb. 16: (89. 1889. De 



Toni, Syll. Alg. 2: 1228. 1894. 



My Bpecimen is a typical example of this unusual Bpecies. As the sounding in 



which it occurred wa.- made off the coast of Alaska, and as the only places heretofore 



" Ehrenb. Mikrog. pi. 83. XIII. 8« amidt, Atlas pi 62./. 18. 1878. II. L. 



Smith. Sp. Diat. Typ. no. 99. This last is probably an emu-. No. 99 is marked 

 C. Hcintillaru Grev., and contains no example of C. radiatus. No. 98 is marked C. 

 radiatus Ehrenb., but is wrong. It is C. nodulifer Schmidt. 



bSchmidt, Atlas pi. 62. f. 1. 1878. 



<■ Proc. R iinli. 16: :>!_'. lss<>. 



dMem. Soc. Phys. el Bist. Nat. Geneva 8 1 1 : pi. W.f.S. 1891. 



eProc. Acad. Phila. 1900: 165 179. pi. 15-16. L900. 



