172 THE ROYAL SOCIETY OF CANADA 



Synedra pulchella Ktz. var. Smithii Ralfs. vll6(3:2:5:2:3)sl6. 

 " ulna Ehr. (Bailey and Kendall). 

 " undulata (Bailey) Greg. (Bailey). 



" n.sp. ? zl08(21 /2)sl3 + , vl25(4:9:4)sl2, vl75(4:9:4)sl2, vl74 

 (4:8:4)sl2, vl68(4.5:9:4.5)sl4, v200(4:9:4) 

 sll, vl44 = 69(4.5:7.5)sl2 + 12(7.5) + 63 (7.5: 

 4.3)sl2. = smooth. Marginal (and all) stria- 

 tion wanting at the centre for a space vary- 

 ing in different specimens from 6 to 15 mu, 

 9 to 12 being most common. The sculpture 

 is marginal and the breadth of the valve 

 instead of tapering regularly often tapers 

 decidedly when approaching the ends for a 

 short distance. Found at several points. 

 Tabellaria floculosa (Roth.) Ktz. v20. A freshwater species. 

 Thalassionema nitzschioides Grun. var. Javanica Grun. v40(3)s7 + , 



v46(2:3:5:2)s8. 

 Thalassiosira Nordenskioldii Cleve. v22(zl8), v27(zl8)s4t:10. v32(zlO) 



4t:10. 

 " gravida Cleve. 



" decipiens Grun. 



" suhtilis ostend. 



Thalassiothrix Fraiienfeldii Grun. vll5(7)s8 + - 



Trachyneis aspera Ehr. var. clepsydra Donk. zl70(33:31 :33)slO, vl85 



(30)sl0. 

 " " " intermedium Grun. vl05(23)s7. 



" " " pulchella Sm. v55(15)sl2, v66(18)sll, 



v93(15(sl4. 

 " " " vulgaris CI. v61(16)sll. 



Triceratium arcticum. Dr. v(144:144:144)s3.7:12 at corners; v(160: 



160:160) s5:12 at corners. Porpoise Bay. 

 " alternans Sm. Found at several points. 



" undulatum (Ehr.) Bright. Dytilum Brightwelli Bailey. 



NOTE: The provisional new specific and varietal names used 

 in the foregoing list are due to Dr. Mackay who does not, however, 

 propose to establish them ; for they have been hurriedly given without 

 even an attempt to avoid their repetition, and merely to mark tem- 

 poiarily some of the more distinct variant forms. Other forms were 

 observed, but more time and material will be necessary for authorita- 

 tive descriptions which should be accompanied with figures. 



It should be remembered too that the specific and varietal nomen- 

 clatures of the diatomaceae require a profound and extensive scientific 



