.MANN DIATOMS OF THE ALBATROSS VOYA< _ M . 1 j 



dies separating the valves make them clearly deserving of a separate generic rank. 

 A reference is made l»\ I.. \Y. Bailey to these forms ha"\ ing been recorded by his father 

 under the generic name Grymaia, which b been published except 



Bynomym. Van Beurck Bpells this genus Ditylum in his text, but Ditylium in his 

 plates. I' 1 ' Toni spells ii Ditylium and says in a note " Nonnulli auctoree acribunl 

 Ditylum, ex. gr. clarus Van Beurck." I prefer to retain the original spelling 



Ditylumsol Van Heur. De Toni, Syll. Alg. 2: L018. 1894. 



eratium Ditylium) sol Van Eeur. Synop. pi. 115. f. 1-2. 1881. Schmidt, Atlas 

 1,1. 152. f. I 9. 1890. 

 There is a close similarity in all the forms of Ditylum thai gives ground for th< 

 picion iliai they may eventually be found i" 1"' varieties of one spe< ■ 

 Found ai station L505H, Santa Cruz Light-House, Monterey Bay, Gal. 



Ditylum undulatum Bright. Mann. 



/' iceratium undulatum Bright. Quart. Journ. Micr. Sci. 6: 154. pl.8.f. 1-5,8. 1858. 

 Cleve, Bih. Sv. Vet. Akad. Handl. 1": 6. 1873. Cleve, Bih. Sv. Vet. Akad. 

 Bandl. 5 : L7. L878. 

 Trie, mint a, undulatum Ehrenb.; Schmidt, Adas///. i:>i.j..)l. 1890. Pant. Beitr. 

 Bacill. Ung. 1: pi 18. f. 164- 1886. 



in undulatum W. Smith; Lewis, Proc. Acad. Phila. 1861: 65. 

 Triceratium Ditylium ehrenbergii Grun.; Van Heur. Synop. pi. 115. f. 7-8. L881. 



Walk, a: Chase, Notes on Diat. 2: 5. pi. .:./. 12. L887. 

 Trio Trans. Micr. Soc. Lond. n. s. 8: 149. pi. 7. f. 5a ! >. L860. 



Van Eeur. Synop. pi 114. f. t. 1881. 

 Ditylum intricatum Grun.; Van Heur. Synop. 196. 1885. 



im brightwellii West, Trans. Micr. Soc. Lond. n. s. 8: L49 (pi. 7. f. 6. 

 doubtful). 1860. Van Eeur. Synop. pi ill./. S-9. 1881. 

 Ditylum trigonum Bail. Bost. Journ. Nat. Hist. 7: 332. pi 7.f.6,10,ll. 1861. H. L. 



Smith, Sp. Diat. Typ. no. 142. 1874. 

 Ditylum inaequalt Bail. Bost. Journ. Nat. Hist. 7: 8:52. pi 7.f. 12-14- 1861. 

 Tuffen Wesl in his discussion of Brightwell's forms confuses matters considerably. 

 He divides the land's '/'. undulatum into two Bpecies, T. intricatum and T. bright- 

 wellii. He speaks of the form he calls T. brightwellii as having inflated margii - 

 refers to Brightwell's figure, which .-'now- thai characteristic; yet in his own figure 

 6a he fails to show that margin. Or, if by "margin" he means outline, the con- 

 vexity he shows in his figure is larking in the figure he mentions in BrightwelTs 

 plate. I take it that both of West's forms are only varieties of Brightwell's species. 

 Ehrenberg's Discopleaundulata probably does nol belonghere; but rather is allied 

 eratium radiatum Bright., a species distinct from this. It is also uncertain if his 

 specimen from the so-called "Bermuda earth." referred to 6 as / undulatum 



is this species. It more probably is his Discoplea undulata. This Ralfs also Looks upon 

 a.< distinct from the present species. Be says c thai it i- probably identical with T. 

 crenatum Kin. Mss. , and that its nearly orbicular outline and crenate margin "dis- 

 tinguish it from T. brigJUwellii." 'Mi these grounds alone it could, however, hardly be 

 bo distinguished. There is no question that what Schmidl call- T. undulatum Bhrenb.d 

 belongs Inn-. 

 Pound at station 4029 H, Bering - 



renb. Mikrog. pi SS. XVIII f. ... L854. 

 6 Ber. Akad. Wiss. Berl. 1844: 27:;. L845. 

 c Pritch. Bist. [nfus. -1. I. 939. L861. 

 d s.hini.lt. Atlas />!. 151. f. 



