r I 



■r- 



MANN DIATOMS OF THE ALBATROSS VOYAGES. 313 



Ral>li. FI. Eur. Alg. 1: 317, 1864. Crun. Denlcschr. Akad. Wieii 48^: G7. 1SS4. 

 Tnum & Witt, Diat. Hayti 24. 1888. 

 Solium Ih^ih, Kril. Overs. DanskeDiat. 22, 52. pL 4-f. 10. 18G3. Grun. Denkschr. 



2,f. 67. 1884. Do T.niL, Syll. Alg. 2:8(>0. 1894. Rabh. FL 



Eur. Alg. 1: 319. 1864. 



The original genus of Elm-nburg, tliough pra(^tically resturcd by Van H(^urck by 

 the inclusion of tbo thrco genera separated from \l by lleibc^rg, contained' some forms 

 that would jiow" be classed i^sewhere. Tlius //. antarctica Elirenl>.^Ms probably a 

 Biddulphia. The gnmnds advanced l)y lleiberg ftjr dividing the genus are of the most 

 trivial character. As Grunow points out,^ Trinacria and Solium are merely triangular 

 and quadrangular examples of llemiauhis; while Corinna diffeis simply in its frus- 

 tules appearing wedge-shaped in zonal \iew. It may be added that certain species of 

 Trinacria are indistinguishable from members of the loose genus Trieeratiinn. The 

 close relation of all these forms to th(^ genus Hiddulpliia is evident; a fact strihin^-^ly 

 illustrated by comparing Ilcmiaulus pohjmorphus Grim, with Bi(hbdphia defjantida 

 Gr(^v.^ The genus Ploiaria Pant., representcKl by the single spe(;ies, P. pctasiformis 

 Pant.jf^ has great resemblance to Ilemiaulus in the valval view; but when seen from 

 the zonal \ iew its somewhat concavo-convex form and its apices unprotruded and des- 

 titute of any spines, make its union here unnecessary. 



Hemiaulus polycystinorum l':hrenb. Mikrog. pi. 36. f. 4Sa-d. 1854; Ber. Akad, 

 Wiss. Perl. 1855: 299. 185G; Phys. Abli. Akad. Wiss. Berl. 1875: 52. p?. ;./. 

 12-15. 187(3. Grun. Denksclir. Akad. Wivw 48-: Go. pi 2.f. 4S-jry. 1884. Schmidt, 

 Atlas pi 14S,f. 23-29. 1889. Pritch. Hist. Infus. ed. 4. 851. 1861. De Toni, SylL 

 Alg. 2: 849. 1894. Boyer, Proc. Acad. Phila. 1900: 740. 1901. 

 Ilemiaulus antarciiciis Weisse in Witt, Verh. Russ. Minn. Ges. II. 22: 39. pi 6.f, 

 1-2. 1886, notEhrenb. 



Found at station 4029II, Bering Sea. 



PLOIARIA Pant. 



IHoiaria Pant. Bcitr. Bacill. Ung. 2: 84. pi 28, f. 403, 405, 1SS9. De Toni, Syll. Alg. 

 2: SfJO. 1894. Van Heur. Treat. Diat. 457./. 186, 1S9C. Boyer, Proc. Acad. Phila. 

 1900: 741. 1901. 



Ikmiaulas Ehrenb. in part; Pant. Beiti-. Bacill. Ung. 1: 50. pi 29. f. 295, 1886. 



Tlu' separation of this genus from Ilemiaulus appears to me justified. The single 

 species at present known differs from any species of Ilemiaulus in several respects. 

 In the zonal view the frustule is strongly concavo-convex and the apices are destitute 

 of vertical projections tipptnl with a claw. The center of the valvi; on one side is 

 raised into a strong dome almost or entirely wanting on the other valve. In the valval 

 view this central area is seen to be unsejnualed from the rest of th(^ valve by rectan'^u- 

 lar boundary lines, such as appear in the similar form of ll<^miaulus, known as Corinna 

 excavata Ileib. So far as I know, the gt^nus is exclusively fossil, and J liave h(^ard of 

 no cases w1ut(^ th(^ frustules occur in connected series, as they d(j in Ilc^ndaulus. 



Ploiaria petasiformis Pant. Beiir. Bacill. Ung. 2: 84. pi 28. f. 403, 405. 1889. De 

 Toni, SyU. Alg, 2: 860. 1894. Van Hour. Treat. Diat. 457./. J86. 1896. Boyer, 

 Proc. Acad. Phila. 1900: 742. 1901. 

 IlemiauluH petasiforvns Pant. Beitr. Bacill. Ung. 1: 50. pi 29. f. 295. 1886. 



Found at station 4029II, Bering Sea. 



a Ehrenb. Mikrog. pi 35 A. XX T.J. 13-15, XXTLJ 15. 1854 

 ^>Denkschr. Akad. Wien 48': 60. 1884. 



c Schmidt, Atlas pi 143. f. 34- and pi 119. f. 10. 

 t^Pant. Beitr. Bacill. Ung. 2: 84. pi 28. f. 403, 405, 1889. 



