366 CONTRIBUTIONS PBOBI Mil NATIONAL HERBARIUM. 



markings of the latter though these Grunow admits are inconstant but ii does not 

 show transverse lines wider and heavier than the oblique, but the three 

 equal and growing finer toward the api is there any trace of a rectangular, 



finely punctate central area. It must I-e said, however, that both these are i 

 minufc m. I have with some doubl left it, as !»«• Toni 



separate -p.-, ies. 



Pound at station 1029H, Bering B 



Gyrosigma speciosum (W. Smith Griff. & Rent. Micr. Diet. 366. pi. 11 

 1875. 

 Pleuroaigma speciosn W. Smith, Ann. Mag. Nat. Hist. II. 9: <;. pi, /. 



lop. Brit. Diat. 1:63. pi. :<»./. 197. 1853. Cleve, Sv. Vet. Akad. Handl 26 

 ii. I v» i. DeToni, Syll. Alg. 2:236. 1891. Pritch. Hist. Infus. ed. I. 917. L861. 

 Rabh. Fl. Eur. Ug. 1: 232. 1864. Griff. & Henf. Micr. Diet. ed. I. pi. 15. I 

 1883. Van Heur. Treat. Diat. 253. pi. 18. / 793. 1896. Cleve. & Grun. - 

 Akad. Handl. 17- 19. 1880. Castr. Rep. Voy. < hall. Bot. 2: 3 

 Perag. Le Diatomisfc I I pi. .'./. 13 19 (not/. i<>. It;/, n doubtful). 1891. 

 Pleurosigma pulchrum Grun. Verh. Zool. Bot. Ges. Wien 19:* 556. pi. .;. /'. :. 1869. 

 Perag. Le Diatomiste 1 ; : I. pi. I.f. 8 (doubtful . 189] (not P. pulchrum Grun.; 

 II. I.. Smith. Sp. Diat. Typ. no. 695. L874 G./ormosum). 

 There is a fine gradation over from this Bpecies bo G.formosum, though the two are 

 i.. be viewed as Bafely distinct. Thus II. I.. Smith's /'. pulchrum is close to G. for- 

 mosum and is best classed there. The real /'. pulchrum < Irun., on the other hand, is a 

 variety of the present species and yet is reasonably close to Smith's form. I do not 

 Eavor placing here as is done by Cleve, /'. tortuosum Cleve; a a diatom of the extreme 

 Donkinia type; nor the inclusion suggested by Peragallo, of /'. tahitiensi Castr. 6 

 Found at station 3607, Bering Sea. 



Gyrosigma thuringicum (Kutz.) Rabh. Sussw. Diat. 17. pi. 5. f. .. I s ">.".. 

 Navicula thuringica Kutz. Bacill. 102. pi. ../. ?7. 1844. 

 Navicula angulata Quek. Treat. Micr. 138. pi 8./. \ 7. L848. 

 Pleuroaigma angulatum W. Smith, Ann. Mag. Nat. Hist. II. 9: 7. />/. /. /. 

 ). L852; Synop. Brit. Diat. 1: 65. pi. fl./. W5. L853. Rabh. PI. Eur. Alg. 1: 

 234. L864. Pritch. Hist. Infus. ed. 4. 918. 1861. II. L. Smith, Sp. Diat. Typ. no. 

 39-391.1874. Cleve & Grun. Sv. Vet. Akad. Handl. 17 2 : 51. 1880. Van 

 II. -iir. Synop. II') pi. 18./. I 5. 1881 85; Treat. Pirn. 351. pi. S.J 

 (not/. :■>>. 261 . 1896. Truan, Anal. Soc. Espan. Hist. Nat. 13: 48. pi. 9.f. I. 

 L884. Griff. & Henf. Micr. Diet. ed. I. 607. /</. 15./. S3. L883. Perag. Le 

 Diatomiste l'-' 1 : II. />l. 5.f. .; /;. L891. De Toni, Syll. Alg. 2: 231. 1891. 

 ('lev.-. Sv. Vet. Akad. Handl. 26 J : ID. L894. 

 Pleurosigma thuringicum Halt'-: Pritch. Hist. Infus. ed. I. 919. 1861. 

 Pleurosigma </<i<i<li<ihiui \Y. Smith, Synop. Brit. Diat. 1: <»•">. pi. 



L853. Rabh. Fl. Eur. Alg. 1: l':;">. 1864. Pritch. Ili-t. [nfus. ed. 1.918. 1861. 



(.rin. & Henf. Micr. Dieted, k pi. 15. /. 34. 1883. Truan, Anal. Soc. Espan. 



Hist. Nat. 13: 15. pl.9./.S. 1884. Perag. Le Diatomiste T : 11. pi. 5./. : s. 



1891. Van Heur. Synop. /</. 18./ l. 



Thai this diatom, known almost universally as Pleurosigma angulatum W. Smith, is 



identical with Kutzing's Navicula thuringica there can be n<> doubt. Although he 



ohiits all data regarding the Btriation, this i> net > m r j » t i - i 1 1 lt . as he usually calls most 



diatom- with a- delicate markings a- tin- one "laevis" or "laevissimus," as he An{>< 



here, h- build is most characteristic. Rabenhorst, Ralfs, Grunow, Van Heurck, 



De Toni. and in fad nearly every author recognizes the identity of the two. De Toni 



aSv. Vet. Akad. Handl. 18 : 5. />!. I.f. 6. 1881. 



bCastr. Rep. Voy. Chalk Bot. 2: 38. r l. 13./. ■■ i ss »>. Perag. Le Diatomiste l 1 : 

 pi. :.(. 10. L891. 



