36S CONTRIBUTIONS PROM THE NATIONAL HERBARIUM 



AMPHIPRORA Ehrenb. 



Amphiprora EhrcMib. Pliyts. Abh. Akad. Wiss. lierl. 1841: 401, 410. IS43. Kiitz. 



Sp. Alg. !);k 1849. Von TTeur. Syiiop. 120. 1881. 

 Entomoncis Elireni). Pbvp. Abli. AkucL Wiss. Berl. 154. 1845. 

 Amph'rampa T?n)ih. Fl. Eur. Alg. 1: 257. 1864. 

 Aviphifropis Tlabh. in Hanst* Bot. Al)hLind. 2: \)\. JS71. firiuK Deuksclir. Akad. 



Wioii 48': 53. pi A.f. '2^5S. 1884. 



Tbo o<nnplif'at(Ml llgnre of these diatoms is duo luaiuly to Iht^ fa< t tliat thoy are, as 

 a rule, contorted spirally about their long axis through an arr of 00" or less, making 

 thel>uild^ which is naviculoid, difficult to understand. The genus is c4ose to Amphora 

 Ehronb., riagiolrupis rfitz,, and Auricula Casti-. 



Amphiprora conspicua Grev. Trans. Micr. Soc. Loud. n. s. 9: Sf>. pi. 10. f. 16, 

 18()l. Moeb. Diat.-taf. p/. -'}(). f. 16. ISOO. Van Heur. Synop. pi. 22his.f, S, 1881. 

 DeToni, Syll. Alg. 2: 335. 189L 



Amphiprora pidchra var. T5. Lewis, Proc. Acad. Phila. 1863: 3Ui. pi. l.f. If). 1864. 

 Van Heurck's figure above represents a doubtful aspect of this species. 

 Found at station 1^604, Bering Soa. 



MASTOGLOIA Thwaites. 



Masfogloia Thwaites; W. Smith, Synop. Brit. Diat. 2: 63. pJ. 54^/^ S40-341, pi. 62. 



/. S88-S89. 185G. Grun. Verb. Zool. But. Ges. Wien 12: 574. pL 5,f. 4-8. 18G0. 



DeToni, Syll. Alg. 2: 313. 1891. Rabh. Fl. Eur. Alg. 1: 20, 260. /. 65, 1SG4. 



PriLch. Ili^t. Lifus. ed. 4. 924. pi. 15. f. 30. ISGl. Van Ili-ur. Synup. GO. pi. 4 J, IS- 



28. 1881 85; Treat. Diat. 153. /. 28, pi. 2.f. 60 GO. 1S9G. O'Meara, Proc, Roy. 



Irish Acad. IF 2; 323. pi 29./. 9-13. 1875. Brnn, Dial. Alp. 92. pL 8./. 28-29. 



1880. Fleve, Sv. VeF Akad. IlandL 26'-: 1 12. 1894. 

 PZewro^fp/zonm Ehrenb. Monabsb.AkadAViss. Berl. 1853:203. 1854, nom,nml.;1856: 



338/)/. /./ 32. 1857; Mikrog. 59. \m. pi S3. l.f. hi 1854. Abh. Akad. Wiss. BerF 



1870: 52, 58. pi. SJlLf. 1-6, 1871. Prilch. Ilist. Infus. cd. 4. 9]5. 18C1. De 



Toni, Syll. Alg. 2: 320. 189h 

 Stigmaphora Wall. Trans. Micr. Soc. Loud. n. s. 8: 43. pi 2.f. 5-8. ISGO. Mueb. 



Diat.-taf. pi 31, f. 5-8. 1890. DeToni, Syll. Alg. 2: 325. 1891. Van Heur. Treat. 



Diat. 156,/. 28a, 189G? 

 Navii'tila Bory in y):irt; Grun. Verb. ZooF Bol. Gea. Wien 13: 151. pi 14. f. 12. 



1S63; in F(?nzl, Reise Novara BoF 1: 99. p/. lA.f. U. 1S70. 



DlckUia P>ork(4cy in part; Thwaites, Ann. Mag. Xat. Hist. IF 1: 17F pi 12. f. K. 

 FSFS. 



Cocconn's Ehr(M]b. in part; Grun, Verb. ZooF BoF Ges. Wien 10: 577. pi 5, f, 

 ion d. ISGO. 



Tills geuus is of most questionable merit. As a convenience in reducing somewhat 

 the uitwieldy geuus Xavicula, it is of advantage, but it is doubtful whether it deserves 

 generic rank on its own merits. The structure of the frustule disj)layH all the charac- 

 teri.stics<)f Xavicula. except in having a more or less evident row of internal h>culi along 



the margins of Iho valves^ from the center toward or to the apices. In this it agrees 

 with ( ertain species of 0oc<*onei8 Ehrenb.. to wbi< b f(fr that reason it was joined l>yGru- 

 now ill his genus, Ortboneis. It (liff(TS, however, from Ooc(*onois in having both 

 valves alike. To admit that this internal plate structure is a generic mark is to invite 

 confusion in some other genera. Leaving out the untenable I)reaking up of Cocconeis 

 already mentioned, there is Navicula cuspidala Kiitz. This diatom I have found at 

 Farmingdale, New Jersey marl pits, both with and without the large internal craticular 

 plates, which when separated from the frustule were known for a long time as Survrlla 

 craticiila Klironb. They are more pronounced structures than the marginal plates of 



