\ 



MANX DIATOMS OF THE ALBATR(^SS VOYAGES. 367 



makes A\ thunngica Kl'itz. asynonyni of /', angulatunt (Quelv.) W. Smith, butsflysufter 

 the former, *'Xonieii aiiteriusi!" Grunow^ givey the following important testimony; 

 '' Navicula thuringlcaKv:,, ist nach Exemplaren von Arteu im Kiitzing't5chen Herbar. 

 identiwclimit PL angulatam, soda.'^s die Art eigentlich VI. Ihannykuui heissen sollte." 

 Van Heure'ky after quoting N, thunngica Kiitz. as a synonym of /'. anyulattnn and 

 following it with an excdamation j)oint, adds this statement; ''Cette espece devrait 

 done porter le nom de IH. thuringira, ve changement dc nom est eependant impos- 

 sible, ear cette diatomee si repandne et si employee fonune test, est universellement 

 connue sous Ic nom donne par ^\^ Smith." TIuto is no question that ihe change of 

 name here made is an unfortunate necessity, as this particular speries is the best known 

 of all the diatoms; and it is with rehu tance that \hv. name which should have been 

 a<x'orded to it over fifty years ago is here i>referred. 



Cleve adds to the above list of synonyms P. i^lrlgosutnW. Smith, ^^ J\ normanii Ralfs,c 

 a!id l\ fnrnn archie firri ClewG,^ These three are alike; but with their blunt apices, 

 smooth outline^ coarser markings, and more sigmoid rai)lie they are very bad examples 

 of varieties of the present species. Dc Tfmi, who gi\'es separate rank to P. nommmi^ 

 unites under 7'. angfdatiun some impossible forms, such as /'. (hUcatahmi W. Smith."* 



The variety corresponding to P. qiiadmhim W. Smith is very alnunhint at station 



3G03. 



Komid at stations 2919, 3200II, 8G03, 3G9C, 453011, Honshu Island, Japan, to Bering 

 Sea, southern t'alifornia, and Santa Cruz Island, West Indies, 



PLAGIOTROPIS Pfitz. 



PlagiotropisVi\tz. in TIanst. Bot. Abhand. 2: 9;i. bS71. Van lleur. Synop. 121. 1881. 

 De Toni, Syll. Alg. 2: 343. 1S91. Tleve & (Jnni. Sv. Vet. Akad. Ilandl. 17-: GO. 



1880. 

 Antphiprom Ehrenl). in part; Greg. Trans. Roy. Soc. Edinb. 21: 505. pi. 12, f. 58, 



1S57. 

 Tropidouids Cleve, in ]>art; Sv. Vet. Akad. Handl. 27"^: 27. 1895. 



I admit this genus with hesitation^ as it is very doubtful if anything is gained I)y 

 se])arating its forms from Anq^hijirora. The genus is bard to miderstand, on account 

 of the contorted and jtellucid ( haracter of the diatoms, I lean toward a union of all 

 its forms under Ami)hiprora; but as 1 have not been able to establish a satisfactory 

 reason for this by an exhaustive study of the different species, I classify the single 

 species found duriiig these ijivestigations under its generally accepted name. If 

 Cleve's contention that this genus should be iut luded in his later genus Tropidoneis 

 is correot, it wouhl have been better to have enlarged and emended this genus instead 

 of creating a new one. 



Plagiotropis van heurckii Grun.; Van Hour, Synop. 122. ph 22bi,9, f, 6-8. 1881. 

 DeToni, Syll. Alg. 2: 340. ISIIh 

 Tropidonds ran lnurvlil Cle\e, Sv. \v\. Akad. TIandl. 26-: 27. 1S91. Van Ileur. 

 Treat. Diat. 2G5. /)/. 6. f. 2ur>. 1S9G. 



F(tun<l at station 2807, Galapagos Islands. 



«Sv. Vet. Akad. Ilandl. 17'-: 02. ISSO. 



h\un. Mag. Nat. Hist. II. 9: 7. pL l.f. 7. 1852. 



cTritch. Hist. Infus. ed. 4. OID. ISO! ; cf. Sv. Vet. Akad. Ilandl. 17'-: 52. pi 3,f, 



G7, 1880. 

 t^Denkschr. Akad. Wien 48-; 105. 1SS4. 



cW. Smith, Synop. Brit. Diat. 1: Gl. pL 21. f. 202, 1853. 



