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MANN DIATOMS OF THE ALBATROSS VOYAGES. 291 



Biddidphia halaaia Bright. QiKirt. Joiirn. Mut. Sci. 7: 181. pi. 9.f. 15. 1859. Mocb, 

 Diat.-Uif. pi. 23. f, 15. 1890. Cleve, In Nordensk. Vega. Exped. 3: 485. 1883, 

 Sdiiiiidt, Atlas pi. 121. f. 5-6. ISSS. II, L. Smith, Sp. Diut. Ty]>. no. G24. 1874, 

 Boyer, Troc. Acad. Phila. 1900: 713. ]n01. 



Zijyoi'eros halaena Ehrenb. Mikrog. pi. 35 A XXXIII. f. 17. 1854; lier. Akad. Wiss, 

 Berk 1853: 529. 1854. Roper, Trans. Micr. Soc. Loud. n. k. 7: 20. 1859. De Toni 

 Sylk Alg. 2: 887. 1894. 



Zijgoccros radiaius Baik Sniithson, <'V)ntr, Kntnvl. 7: 11. pi. l.f. 29. 1854. 



Ai)} philtlras ivitkcsii Ilarv. & Vrdll. Proc. Aead. I'hila. 6: 430. 1854. 



Triccratuifa forniosuni Briglit. Quart. Journ, Micr. Sci. 4: 274. pi. 17. f. 8. 1856. 



Much. Diat.-taf. pi. 9. J. 8. 1890. 

 Tnceratiuvh q^iodramjalarc Grev. Trans. ^Ticr. Soc. Lond. n. s. 13: 10. pi. 2.f. 26. 



1SG5. Moeb, Diat.-taf. pL GS.J. 2G. 1890. Sclimidt, Atlas p?. 81. f. 3. 1885. 

 Amphitetras qitadrangttlaris Do Toni, Sylk Alg. 2: 904. 1894. 

 Tnceratium quinqnelobatuTn Grev. Tnins. ^Micr. Soc, Lond. n. p. 14: b3. pL 9./. 21. 



1806, Mocb, Diat.-taf. pi 73. f. 2L 1890. Schmidt, Atlas pi. 79. J. 8. 1882. 



Eng. & Pr. Pflanzenfani. 1'": 91,/. 155B. 189G. 

 Amphipcnlas quinqadobala Do Toni, Sylk Alg. 2: 911. 1894. 

 Triceratiam finnaai Grev. Trans. Micr, Stic, Lond. n. s. 12: 93. pi. 13. f. 8. 18G4. 



Mocb. Dial.- taf. pi. 61. f. 8. 1890. De Toni, Sylk Alg. 2: 92k 1894. 

 Biddidphia fof^mosa V^'dlk. ik Tkase, Xotes on Diatoms 1: 2. jd. 2. J. 9. 188G, 



This speciea ia Cleve's type of the genus Trigonium. 



Probably no specieti shows mure variability than this in size, outline, fineness of 

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

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

 description??. 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 

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

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

 Mirieties of the same polymorphic species, and this conclusion agrees in the main Avith 

 that of some of the authors cited above. Thus Zygoceros lalaena Ehrenb., which is 

 Z. radiaius Bail., and Biddidphia hahuna Briglit., is an oval with two instead of three 

 rouiuled apices. It is frequent at station 4029II. It is also in II. L. Smith's Type 

 no. 024 and makes up a considerable portion of type no. 59G, marked Triceralium arc- 

 ticum, in whicli the two-angled and three-angled varieties can be seen side by side 



and are so absolut(4y alik(^, except in tin; numl)er of angh^s, that no (piestion of their 

 specific identity (^an remain. One of the sliders accompanying this report contains 

 thr(;e sp(Hamens from station 3G03; tlu^ first is Grunow's variety ealifoTnica^ the 

 second a quadrate specimen of T. arcliciiTYi, and the third a quachute specimen of 

 T.Jormosnm. The variety ca^i/ormca also occurs abundantly at stations 2807,2859, 

 2923, 3G03, 3G01, 3G92II; beautiful specimens of typical T. qaadrangidarc Grev., at 

 station 308811; T. quinquelohaiiun Grev., at station 2808; a variety close to T. ant- 

 ardicamjan.y at stations 2807 and 3G04II; T.fum uiti Grev., at station 3G88IL Ecgard- 

 ing this last the border in my specimens are not quite so massive as in Greville's 

 drawing; but the border varies gri'atly in all members of this species. It is certainly 

 a small and stout variety of this specic^s. My specimens of it averaged 0.0G5 mm. in 

 diameter. I have not included T. anfarcticifm Jan., as the ideiitifieation in my speci- 

 mens is not exact. It is i^rol)ably also a variety. The placing of some of tlie above 

 in Triceralium, others in Amphitetras and others in Amphip<Mitas by De Toni is unac- 

 countable; also his uniting the five-anghnl 7\f()^nosuvl^yii\l ilia live-angled T.faviis 

 under Brightwelks invalid name T. grnnde. 



Found at stations 2G80H, 2807, 2808, 2&44, 2859, 2923, 326311, 3003, 3G04, 3G04II, 

 3G8311, 3GSSII, 3691II, 3G92II, 3698, 402511, 1029II, 451G11, Galapagos Islands to Bering 

 Sea and south to Honshu Island, Japau 



