MANX DIATOMS OF THE ALBATROSS VOYAOES. 251 



the cells not smallj but with very delicate walla; nearly uniform in wize until within 

 one-fifth of the radius from the margin, then rapidly decreasing to the margin; no 

 dots or puncta within the hexagons; interradial lines frequent toward the margin; 

 border a thin hyaline band; outline uniformly irn^gular by depression of one side. 



Diameter of valve from 0.138x0.109 mm. to 0.080X0.071 mm. 



Type in the U. S. National Mu.seum, Tso. 590120, from station 2807^ Galapagos 

 Islands, April 4, ISSS; 812 fathoms, bottom of (Jlobigerina ooze and coral mud; col- 

 lected also at station 3013II, Hawaiian Islands. 



This form is not to be confused with the irregular, generally sul)triangular exam- 

 ples of C. heteroporus Ehrenb., cla'^sed as C. dea^escens irregularis Grun.'i The far 

 greater delicacy of the networkj the absence of papillae^ and tlu* uniformity in the 

 liexagons over the greater part of the valve, clearly distinguishing tlunn. It is very 

 abundant at both the above stations, the first of whicli is close to the Galapagos Islands 

 and the second closo to the Hawaiian Islands. This unusual form must therefore 

 be looked upon as a subtropical littoral species. 



Coscinodiscus denarius Schmidt^ Atlas pl.57.f. 19-22. 1878. Ratt. Proc. Roy. 

 Soc, Edinb. 16: 504. 1889. De Toni, SylL Alg. 2: 1238. 1894. 

 Coscinodiscus variolatus Castr. Rep. Voy. Chall. Hot. 2: 155. pL 2. J. 5. 1886. 



It is douluful if this has sufficient specific difference from C. symnietricus Grev. to 

 warrant the above name. It is certainly not sufficiently different from the figures 

 so named by Schmidt,^ Compare also Greville's original figure, c 



Found at station 3097, off central California. 



Coscinodiscus elegans Grev. Trans. Micr. Soc. Lond. n. s. 14: 3. pL /./. 6, 18GG. 

 Schmidt, Atlas pi 58. f. 7, pi. 163. J. 10. 1878. Pant, lieitr, Racill. Ung. 1: 73. 

 pi 16. /. 141 (?), pi. 24./. 216. 1886. Jan. Diat. Gaz. Exped. j)l 4, J. 6. Cleve 

 & Moll, type no. 1G4. Truan & Witt, iJial. liayti 14. pi, 2.f, 22. 1888. Ratt. 

 Proc. Roy. Soc. Edin!). 16: 585. 1889. De Toni, Syll. Alg. 2: 1293. 1894. Moeb, 

 Diat.-taf. pi 10. f. 6. 1890. 

 Coscinodiscus maryarilaceus Castr. Rep. Voy. ChuU. Jiot. 2: 104. pi 18. f. S, 188G, 



Of the above hgures the first of Pantocsek's is worthless; those in Janisch and in 

 Luard & Witt must be looked upon as repros<^nting (extreme vari<^ties. 



fn the specimen accompanying this report th(^ frustule ha^ two valv(\s quite differ- 

 ent in the arrangement of the beading, a good comuientary on the constantly repeated 

 absurdity of making '*new species" out of such trifles. 



Found at station 3G04H, Bering Sea. 



Coscinodiscus excentricus Ehrenb. Phys, Abh. Akad. Wiss. BerL 1839: 14G. 

 1841; 1841: 323. pi 3. VII. / 5, 1843; Mikrog. pi 18. /. St, pi 21. / e. 

 W. Smith, Synop. Brit, Oiat. 1: 23, pi 3. /. 38. 1853. Schmidt, Atlas pi SS. 

 /. 46-49; Jahresb. Komm. Deut. Meere 2; pi 3 J, 36-38. 1874, Grun. Denkschr. 



Akad, Wien 48-: 84. pi 4D. f, 7. 1884. 



/ 



7, 8, 1881, Jan, Diat. Gaz. Exped. pi 2. J. 3, pi 6. f. 3, 7-11, 11, L. Smith, 

 Sp. Dial. Typ. no. 93. 1S74. Van Ileur. Typ. Diat. Belg. no, 529, 530. Cleve 



ype 



Ratt, Proc, 



Roy. Soc. Edinb. 16: 4G1. 1889. De Toni, Syll. Alg. 2: 1210, 1894. 

 Odonlodiscm excentricus Ebrenb. Ber. Aka<l. A\'is.s. Berl. 1845: 79. 184G, Schmidt, 



Jahreso. Komm. Deut. Meere 2: 94. 1874. 

 Eupodiscus excentricus O'Moara, Quart. Joiirn. Micr, Sci, 7: 245. jd. 7./. 2. 18(17. 



>hjeb. Diat.-taf. pi 77./, 2. 1890, 

 Coscinodiscus minor Sclimidt, Atlas pi 113. f. 9. 1888. 



— . — J : — 



a Schmidt, Atla^ pi 61./. 7. 187S. 



^>0p. cit. pi 57./. 25-27. 



cTranw. Micr. Soc. Lond. Ji. ts. 9: G8. pi 8./. 2. ISGl. 



