3G6 CONTKinUTTOXS FROM THE NATIONAL HERBARIUM. 



markings of tlio latter (tliougli these Grunow adniiLs are ineonstant) but it does not 

 show transverse liueri wider and heavier than the ()l)li(jue, but the ihree sets about 

 equal and growing fuK^r toward the apicefl. Nor is there any trace of a roctanLniUir. 

 finely punctate central area. It niu^t be said, however, that both these are (lose to 

 jninute forms of G. rujidimu I have with some <loubt left it, as De Toni does, as a 

 separate species. 



Found at station 4029II, Bering Sea. 



Gyrosigma speciosum (W. Smith) Criff, A Ilenf. Micr. Diet. 35G. pL 11. f. 28, 

 1875. 



Plrurosigma sprnosum \\\ Smith, Ann. Mag, Xat. Hist. 11. 9: 6. pA, l,f. S. IS52; 

 Synop. r>rit, Diat. 1: 03. pL 20. f. 197, 1S5:J. Cleve, Sv. A^et. Akad. Han<ll. 26^': 

 44. 1894. DeToni, Hyll. Alg. 2: 2'M]. ISDL TiUch. Hist. Infns. ed. 4. 917. IS(i]. 

 Rabh. Fl. Eur. Alg. 1: 2:52. 1SG4. Griff. & Ilenf. Micr. Diet. ed. 4. pL 15. f. ^>S, 



1883. Van Hour. Treat. Diat. 253. pl2H.f. 7.9;?. 181)6. Oleve. & Grun. Sv. Vet. 

 Akad. Handl. 17-: A\), bSSO. Castr. Rep. Voy. <1iall. P.ol. 2: 37. pi. 28. f, 2, 188G. 

 Terag. Le iJiatoniiste l^'-': G. p)L 2.f. 13-19 (not/ 10, 12; f. 11 doul)tful), 1891. 



rifurosigma puh-hrum i\n\\\. Verb. Zool. Bot. Oes. Wien 19:-55G. ;)/. 4.f. 2. 18G9. 

 Perag. Le Diatomi^^(e l"* ■": 4. p>L l.f. 8 (doublful). 1891 (not 7". pidchrvm Crun.; 

 IT. L. Smith, Sp. Diat. Tyj). no. G95. lS74=n, fontfostnn). 



There is a fine gradation over from this species to C . formosum^ though tlie two are 

 to he viewed as safely distinrt. Thus II. L. Smith's /'. pnkhrum is (4oso to CI. for- 

 mosum and is best classed there. The real P. pulrhnnn Gr\Mi., on the other hand, is a 

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

 favor placing here, as is done by (Mevo, P. torfi/osmn dove/' a diatom of the extreme 

 Donkinia type; nor the inclusion suggested l)y Peragallo, of P. (ahilicnsc Castr. ?^ 



Found at station 3G07, Bering Sea. 



Gyrosigma thuringicum (Kutz.) Ral)li. Sussw. Diat. 47. pJ, 5.f, 4. ISS."^. 



Kavicida thunngica Ki'itz. Bacill. 102. pJ. 4./, 27. 1844. 



Navicula angulata Quek. Treat. Micr. 438. pL 8,f. 4 7. 1848. 



Plcurosigma angifhttitm \\. Smith, Ann. Mag. Nat- Hist. 11. 9: 7, pL 1. f. 

 7-9. 1852; Synop. Brit. Diat. 1: 65. pL 21. f. .J0r>, 1853. Rabh. PI. Eur. Alg. 1: 

 234. 18G4. Pritrh. Hist. Infus. ed. 4. 918. ISGI. II. L. Smith. Sp. Diat. Typ. uo. 

 389-391.1874. Cleve & Grun. Sv. Vet. Akad, Ilundl. 17^': 51. 18S0. Van 

 Hour. Synop, 115, pi 18. f. 2 5. 1881 85; Treat. Diat. 351. pL G.f. 257. 259-260 

 (not/. 258, 261). 189G. Truan, Anal. Soc. Espan. llisi. Nat. 13: 48. pi 9 J. 1. 



1884. Griff. & Ilenf. Micr. Diet. ed. 4. G(>7. pi 15. f. SS. 1883. Perag. Pe 

 Diatomiste l^'-'^: 11. pJ, 5.f. S-6. 1891. Do Toni, Syll. Alg. 2: 2:5P LSfM. 

 Cleve, Sv. Vet. Akad. Ilamll. 26-: 40. 1894. 



PLurosigtna iharinglauti Ralfs; Prilch. Ilist. Infus. ed. -1, 919. 1861. 



Plcurosigma quadniium W. Smith, Synop. P>ril. Diat. 1: Gf^. pi 20./. 204, 204B. 



1853. Rabh. Fl. Eur. Alg. 1: 235. 18G4. Prileh. Hist. Infus. ed. 1. Iil8, ISGL 



Griff. & Ilenf. Micr. Diet. ed. 4. pi 15j. S4. 1SS3. Truan, Anal. Soc. Espan. 



Hist. Nat. 13: 45. pi D.f, 8, 1884. Perag. Le Diatomiste l^'-'; 11. pL 5.f. 7-8, 



18!)I. Van Iteur. Synop. pi 18. f. 1. 



That this diatom, known ahnost universally as Plifvo.^igwa angulafini} \\\ Smilh, is 

 identit^al with Kiilzing's Navicula thmngica there can bo no doubt. Although he 

 omits all data regarding the striation, this is not surprising, as he usually calls most 

 diatoms with as delicate markings as this one 'Maevis'' or " laevi.^sinuis," as he does 

 here. Its build is most characteristic*. Rabenhorst, Ralfs, Grunow, \'an Ileurck, 

 D(; Toni, and in fact nearly every author recognizes the identity of the two. De Toni 



«Sv. Vet. Akad. Handl. 18"': 5. pi l.f. 6. 1881. 



^> Castr. Rep. Voy. Chalb Bot. 2; 38. pi 23. f, 4. 188G. Perag. Le Diatomiste l'"^: 

 pi 2.f. 10. 1891. 



