IU\S CONTRIBUTIONS FROM Mil. NATIONAL HERBARIUM, 



AMPHIPRORA Ehrenb. 



I Ehrenb. Phys. Abh. Akad. Wise. Berl. 1841: mi. 410. 1843. Km/.. 



Ug, 93. L849. Van Heur, Synop. L20. L881. 



Ehrenb. Phys. \Mi. tkad. Wise, Berl. 154. 1845. 

 I vmpa Rabh. I'l. Eur. Alg. 1: 257. 1864. 



i Elabh. in SanBt. Bot. \bhand. 2:94. L871. <.run. Denkschr. Akad. 



Wien 48 : •".:;. p/. I f ,. L884. 



The complicated figure of these diatoms i- due mainly to the facl that the) are, u 

 a rule, contorted spirally aboul their long axis through an an- of 90 -r leas, making 

 the build, which is naviculoid, difficult to understand. TIm-<_'«mhi- is close to Imphora 

 Ehrenb., Plagiotropis Pfits., and Auricula Castr. 



Aniphiproni conspicua Grev. Trans. Micr. Soc. Lond. n. s. 9: 86. pi. /". /'. 16. 

 1861. Moeb. Diat.-taf. pi. 40./. 16. 1890. Van Heur. Synop. pi. ttbii. f. I L881. 

 D.- Toni, Syll. Alg. 2: 335. L891. 



Ampkiprora pulchra var. B. Lewis, Proc. tcad. Phila. 1863: .".it;, pi. i. f. in. 1864. 



Van Heur< -k"> figure above represents a doubtful aspect of iln~ species. 



Pound at station 360 1. Bering Sea. 



MASTOGLOIA Thwaites. 



Mastogloia Thwaites; W. Smith, Synop. Brit. Dial. 2: <;:;. pi. , 

 f.S8S S89. 1856. Grun. Verh. Zool. Bot. Ges. Wien 12: 574. pi. ■'>./. | 8. I860. 



DeToni, Syll. Alg. 2: 313. L891. Rabh. I'l. Fair. Alg. 1: 20, 260./ 65. L864. 



Pritch. Bist. [nfus. ed. 1.924. pi. tS.f.SO. L861. Van Heur. Synop. 69. pi. .../. IS 

 L881 B5; Treat. Dial. L53. / ?5, pi. /../'. 60 66. L896. O'Meara, Pi 



Irish Acad. II. 2: 323. pZ. //'./'. 9 M. L875. Brun, Dial. Alp. 92. pi. 8. 



L880. Cleve, Sv. Vet. Akad. Handl. 26-': 1 12. 1894. 

 Pleurosiphonia Ehrenb. Monatsb. Akad. Wiss. Berl. 1853:203. 1854, nom.nud.;1856: 



338pJ. /.,/". St. L857; Mikrog. 59. m.pl.SS. /../'. /;. L854. Abh. Akad. Wiss. Berl. 



1870: 52, 58. pi. S.III.f. l 6. L871. Pritch. Hist. Enfus. ed. 4. 915. 1861. De 



Toni, Syll. Alg. 2: 326. L891. 

 Stigmaphora Wall. Trans. Micr. Sue. Lond. n. b. 8: 13. pi. .'./. 5 8. I860 Moeb. 



Di&t.-tai.pl.Sl.f.S 8. L890. De Toni, Syll. Alg. 2: 325. 1891. Van Heur. Treat. 



Dial. L56./. 28a. 1896? 

 Navicula Bory in pari: Grun. Verh. Zool. Bot. Ges. Wien 13: 151. pi. l',. f. /.'. 



L863; in Fenzl, Eteise Novara i'.-.i. 1: 99. pi. lA.f. 11. 1870. 

 Dichieia Berkeleyin part; Thwaites Ami. Mag. Nat. Hist. II. 1: 171. pi. tt.f. A'. 



IMS 



Cocconeis Ehrenb. in pari: Grun. Verh. Zool. Bot. Ges. Wien 10: 577. pi. 



inn ,1. L» 



This genus is of most questionable merit. As a convenience in reducing somewhat 

 the unwieldy genus Navicula, i1 is of advantage, but il is doubtful whether it desi 

 generic rank -mi its own merits. The structure of the frustule displays all the charac- 

 teristics of Navicula. excepl in having a moreor less evident row of internal loculi along 

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

 with certain species of Cocconeis Ehrenb., to which for thai reason ii was joined l>y (i ru- 

 in. w in his genus, Orthoneis. h differs, however, from Cocconeis in having both 

 valves alike. To admit thai this internal plate sir in •lure is a generic mark is to invite 



confusion in son ther genera. Leaving out the untenable breaking up of Coc< is 



already mentioned, there is Navicula cuspidata Kutz. 'Phi- diatom I have found at 

 Farmingdale, New Jersey marl pits, both \\ ith and without the large internal craticulai 

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

 craticula Ehrenb. They are more pronounced structures than the marginal plates of 



