MANN DIATOMS OF THE ALBATROSS \ <»\ \, •_><)] 



Biddtdphia balaena Bright. Quart. Journ. Micr. Sci. 7: \&l.pl.9.f. 15. 1859. Moeb. 



Diat.-taf. pi. IS. f. 15. L890. Cleve, in Nordensk. Vega. Exped. 3: 



Schmidt, Atlas pi. 121. f. 5 6. L888. II. I.. Smith, Sp. Diat. Typ. no. 624. 1874. 



Bojwr, Proc. Acad. Phila. 1900: 71:;. L901. 

 Zygomros balaena Ehrenb. Mikrog. pi. $5 A XXXIII.f. 17. L854; Ber. Akad. Wise. 



Berl.1863: 529. L854. Roper, Trans. Micr. Soc. Lond. n. s. 7: 20. L859. !»• Toni 



Syll. Alg. 2: 887. L894. 

 Zygoceros radiatus Bail. Smithson. Contr. Knowl. 7: II. /;/. /./. .''. I v ">i 

 AmpkUetras wilkesii Barv. <& Bail. Proc. Acad. Phila. 6: 130. L854. 

 Triceratium formosum Bright. Quart. Jourri. Micr. Sci. 4: 274. pi. 17. f. -. L856. 



Moeb. Diat.-taf. pi. 9.f. 8. L890. 

 THceratium quadrangulan Grev. Trans. Micr. Soc. Lond. u. .-. 13: I'), pi. .-./. *6. 



1865. Mod). Diat.-taf. pZ. 63. f. 16. L890. Schmidt, Atlas pZ. W./ .;. :- 

 Amphitetras quadrangularis De Toni, Syll. Alg. 2: 904. L894. 



Triceratium quinquelobatum Grev. Trans. Micr. Soc. Lond. n. b. 14: 83. pZ. '- 



1866. Moch. Diat.-taf. pi. 73. f. U. L890. Schmidt, Atlas pi. 79. f ?. L882. 

 Eng. & Pr. Pflanzenfam. l lb : 91./ 155B. I896. 



AmpMpentas quinquelobata De Toni, Syll. Alg. 2: fill. L894. 



Triceratium firmum Grev. Trans. Micr. Soc. Lond. n. b. 12: 93. pi. 13. f. 8. L864. 

 Moeb. Diat.- taf. pZ. <;/./. 8. L890. De Toni, Syll. Alg. 2: 924. L894. 



Biddulphiaformosa Walk. A: Chase, Notes on Diatoms 1: 2. pi. ../. 9. I- 



This species is Cleve's type of the genus Trigonium. 



Probably no Bpecies shows more variability than this in size, outline, finen< -- 

 marking, and absence or presence of central area. Nor is it possible to decide on the 

 identity of the above names without specimens corresponding to the figures and 

 descriptions. I have been able to do this on account of the large number of sea 

 dredgings, widely separated from each other and containing abundant quantities of 

 these forms that have been examined for this report. By comparison of many exam- 

 ples accurately agreeing with the above names I am convinced they all represent 

 varieties of the same polymorphic Bpecies, and this conclusion agrees in the main with 

 that "f some of the authors cited above. Thus Zygoceros balaena Ehrenb., which is 

 Z. radiatus Bail., and Biddulphia balaena Bright., is an oval with two instead of three 

 rounded apices. It is frequent at station -1029H. It is also in II. L.Smith's Type 

 no. 624 and makes up a considerable portion of typ.- no. 596, marked Tricerativ 

 ticum, in which the two-angled and three-angled varieties can be Been .-id'- by Bide 

 and are so absolutely alike, excepl in the number of angles, that no question of their 

 specific identity can remain. One of the slides accompanying this report contains 

 three specimens from station 3603; the first is Grunow's variety mrtifornica, the 

 second a quadrate specimen of T. arcticum, and the third a quadrate specimen of 

 T. formosum. The variety californica also occurs abundantly at stations 2807, 

 2923, 3603, 3604, 3692H; beautiful specimens of typical T. quadrangulan Grev., at 

 station .".nssll; '/'. qnlntiinlobahi m (Jrev., at station 2808; a variety close n- T. ant- 

 arcticum Jan.. at station- 2807 and 3604H; T. firmum Grev., at -'.it ion 3688H. Regard- 

 ing this last the border in my specimen- are no- quite so massive as in Greville's 

 drawing; but the bonier varies greatly in all members - t this species. It is certainly 

 a -mall and stout variety of this Bpecies. My specimen.- of it averaged (>.oi;;> mm. in 

 diameter. I have not included T. antarcticum .Ian., a- the identification in my - 

 men.- is not exact It is probably also a variety. The placing of -"me of the above 

 in Triceratium. others in Amphitetras and oilier- in A in phi pent a- by De Toni i- unac- 

 countable; also his uniting the five-angled T. formosum with the five-angled T. 

 under BrightwelTs invalid name T. grande. 



Found at stations 2680H, 2807, 2808, & I !. 2859, 2923, 3263H, 3603, 3604, 3604H, 

 3683H, 3688H, 3691H, 3692H, 3698, W25H, W29H, iM'dl. Galapagos Islands to Bering 

 Sea and south to Bonshu island, Japan 



