264 CONTRIBUTIONS FROM Mil NATIONAL HERBARIUM. 



The name ' Eupod Ehrenbergo ought i" be dropped oul of considera- 



tion, a- there is no indication "i" the character of the diatom the author had in mind 

 Ralfs'e however, di ffers in no respect, except in its peeudonodule, from I 



btxlis Ehrenb.* and especially from the figures in Schmidt's Atlas | 



Pound ai -urn. : - 164 'II. Kuril Islands, and 3688 II. Sea of < >kh..t~k. 



Actmocyclus tesselatus Eloper Ralfs in Pritch. Hist. Infus. ed. 1.835. 186] 



Quart. Journ. Micr. Sci. 6: 19. /"'. S. f i i. 18 

 " ; . Diat.-taf. pi IS 



UaGrun.; Van Heur. Synop. pi. Ill L881. Ratt. Journ. Roy. 



Micr Soc. 8-: 57. L888. I>« Toni, Syll. Alg. 2: 1087. L894. 



As 1:..- been j>< >i m «*<1 oul in the discussion of the genus, 1 1 1 « - sole difference between 

 Actinocyclus and Coscinodiscus is the presence in the former of the pseudonodule. 

 Although this species contrasts strongly with others of the genus because "i" its reticu- 

 lated marking, ii does not differ in that respect from Coscinodiscus, where such mark- 

 re ili«' dominant on< 8. I a e, therefore, no reason to plan this in a new genus. 

 The pseudonodule is less dense ami convex than in most Actinocycli, 1 1n >i i«rl i there 

 t< eptions even m this; but there can be no question that ii is the homologue of 

 that structure. 



indal stations 2680H, 2690H, between San Francisco and Hawaii. 



CRASPEDODISCUS Ehrenb. 



Craspedodiscus Ehrenb. Ber. Akad. Wiss. Berl. 1844: 200. 1845; Mikrog.pZ. 18. f. 108. 

 Pritch. Bist. Infus. ed. I. 831, 939. L861.' De Toni, Syll. Alg. 2: 1198. 1894 

 (iriii. ,v. Benf. Micr. Diet. ed. 3. •-'(»:'.. j>l. ;.;./. :\. L875. Bright. Quart. Journ. 

 Mi«r. s,i. 8: '.m. />/. 5.f. 6, pi 6.f: l '.. Med,. Diat.-taf. pi 19. f. 12. L890. 

 inodUcus Ehrenb. in part; Km/. S|». Alg. 126. L849. 

 Pyxidicula Ehrenb. Ber. Akad. Wiss. Berl. 1844: 85. L845, in part. 



• \ in part; Grun.; Schmidt, Atlas pi. 66. f. 6. L888 

 Hyalodiscus Ehrenb. Ber. Akad. Wiss. Berl. 1853: ."CM L854, in pari: Mikrog. />!. 

 a b. L854. 



Although this genus i> "i" questionable validity ii is not possible ;ii this time to dis- 

 tribute it- members among the two or three genera which ii most nearly resembles. 

 It stands closest i" Coscinodiscus, as is evident by such examples of Craspedodiscut 

 cosdnodUcus Ehrenb. a- that figured in Schmidt. « Ontheother hand, ii lead- over 

 impercepl ibly into Porodiscus Grev., as in the case of Schmidt's figure,^ which Grunow 

 calls Craspedodiscus nhl<>ii<jus. bul which Rattray l<><>k- upon, and rightl; 



oblongus Grev. Nor is it surprising thai in such cases of Brightwellia as have a 

 very minute ring of beads separating the central portion from the outer hand of the 

 valve, this ring should be looked upon as essentially the same as the suture that usually 

 separates these two port ions in 1 Craspedodiscus. ' [tis, howe> er, best to hold this genus 

 distinct; and accordingly the union of it with Coscinodiscus by KUtzing? has been 

 generally disregarded. 



El - nb B( r. Ucad. Wiss. Berl. 1855: 302. L8 

 bPhys. Abh. Akad. Wiss. Berl. 1841: 412. pi. /. III. J 1i L843. 



midt, Atlas pi • L881. 



dOp. « it../'. ; 9. 



> Proc. Roy. Soc. Edinb. 16: 674. L889. 

 rCf. Bright. Quart. Journ. Micr. Sci. 8: !»•">. r l. 5./. 6. L8( 

 •i Km/. Sp. Ug. L26. L849, 



