254 CONTRIBUTIONS FROM TIIK NATIONAL JIERBARIUM. 



1 liuve here figured a form common in fc;e\ tiul dredgings, which, according to pres- 

 ent interpretations, passes under the above nauie. I do lliis in order to illustrate a 



confusion in the taxonomy of this species that should receive attention. Anyon<^ who 

 will compare Grcwille'a original figun? of C.rohustus^ with tiie oritrinal figure of 

 Ehrenberg's C, marginatus ^ will see lilth^ resemblance between llu^in. Yet Grunow, 

 Schmidt, Pantocsek, Rattray, and o1h(Ts give no satisfactory marl;y of distinction, 

 and we have all sorts of discordant opinions connected willi most of the modern 

 figures. Grunow gives us, on the one hand, a C. robudus intermedia Grun.f^ which 

 Rattray makes C. inarginaius intermedia Ratt.,f^ and on the other hand Grunow 

 gives a C. marginatus submaryinata Grun.,'' which Rattray puis under C. robustxis 

 Grev.^ Rattray furtlu^r states that though iIhv oiiginal slide of Greville's ('. rohishts 

 is not available, two slides marked l>y him (Greville) '' C\ robvstus'' now in the British 

 Museum are C. marginatus Ehrenb. In vi(nv of the foregoing facts I offer the sugges- 

 tion that someone who has access to the material sift out tliese forms,. and, if neces- 

 sary, drop Greville's species entirely in favor of Ehrenberg's. The name C. mar- 

 ginatus might necessarily be retained, instead of the earlier C. Unihatus, because of 

 the uncertainty of the two figures Ehrenberg gives for that species./ Under present 

 conditions no such thing as a positive identification is possible. 1 have labeled some 

 specimens that show a narrow border and an absence of radial arrangement, with 

 obscure or broad papillae in the hexagons, C. robvstus Grev., and others, wdth broad 

 and massive borders, somewhat radial and slightly diminishing areolation showing 

 pronounced papillae, C. marginatus Elirenb.; but though the best possible under the 

 present circumstances, these can not be looked upon as critic^al identincati(ms. 



Diameter of valve here figured, 0J7G ]nm. 



Found at stations 33G1II, 3712H, off Ranama and Okhotsk S(^a. 



Coscinodiscus nitidulus Grun.; Schmidt, Atlas pi. 58, f. M-2U\?^1^ {not pi. 113, f. 

 IS. 1888). Van Ileur Synop. pi. lS2,f, 2. 1881. Pant. Fieitr. Hacill. Ung. 1: 

 73. pi. 24. f. 214. 1880. Ratt. Proc. Rov. Soc. Edinl). 16: 480. 1889. De Toni, 

 Syll. Alg. 2: 1222. 1894. Jan. Diat, Gaz. Exped. pi. 5 J, Id, 

 Found at station 45I0II, off Lower Galifornia. 



Coscinodiscus nitidus Greg. Trans. Roy. Soc, Edinb. 21: 499. pi 19. f. 46. 1856. 

 Schmidt, Atlap p/. 68. /. 16-19. 1878; Jalnvsb. Komm. Deut. Mcere2: 94. pi S. 

 f. 32. 1874. Pritch. Hist. Infus. ed. 4. 831. pi 8. f. IS. 18G1. Jan. Diat. Gaz. 

 Exped. pL 5.f. 12, 14-16 (not /. 13), Pant. Beitr. Bacill. Fng. 1: 75. pi IS. 

 f. 166, Van TIeur. Synop. Suppl. pL C. f, 41. 1885. Wolle, Diat. N. A. pi 94. 

 f. 22-23. 1S90. Ratt. Proc, Roy. Sue. Edinb. 16: 478. pi 1. /. 21. 1889? De 

 Toni, Syll. Alg. 2: 1221. Cleve & Moll, type no. 150, 155, 208, 210, 257, :ill. 

 Coscinodiscus foramlnosas Grev. MS. in Coll. Brit, Mu.^. 



This and the former species phow (xjn.'^idf^rable repemblan(H> to ccTtain members of 

 the genus Stictodisrus.^ 



Found at station 2807, Galapagos Islands. 



« Trans. Micr. Soc. Lond. n. s. 14: pi l.f. S. ISGG. 



^Ehrenb, Mikrog. pi 18. f. 44^ 1854. 



<^Denkschr. Akad. Wien 48^: 72. 1884. 



dVroQ. Roy. Soc. Edinb. 16: 511. bS89. 



^Op. cit. 512. 



/Ehrenb. Mikrog. pi 20. f. 29a-b, J854. 



gCl. Schmidt, Atlas pi, 202. f. 4- 189(> and Journ. Quek. Micr. Chil) II 3: pi 5 

 /. 7. 1887. 



