_.>'J CONTRIBUTIONS PROM MM NATIONAL HERBARIUM. 



Idbyrinthtu I Quart. Journ. Micr. Sci. (5: 21. pl.S. /'. ?a b. L868. 



M «b Diat.-taf. pi. 19. f. : a b. L890. Pritch. Bist. Infus. ed. I B31. Rait. 

 Pro i: Soc. Edinb. 16: t:i L889. Cleve 4 Moll, type do. 276. CK Toni, 

 Syll. Alg. 2: 1215. 1894. Grun. Denkschr. Akad. Wien« 48 a : 73 L884. 



As ih« centra] portion o! ft sol Wallich and this Bpecies are almost identical, and 

 as tin- outer border is weakly Bilicined and easily destroyed, specimens of the two 

 may easily be confused, h maj ultimately be found thai the two are only striking 

 varieties of the same Bpecies, in which case O'Meara'e E. excentricus would represent 

 an intermediate form. Comparing it with the second figure of C.sol, w here the invest- 

 ing ring is greatly reduced, it is easy to see ho* an extensi I the puncta into 



lines in the ot hem ise hyaline border of < t'Meara'e form, and a reduction in the deposit 

 of silica would give ue G sol. Variation in these respects is by no means unknown. 



An analogous case will be found described under ft robustus Grev., where in b e 



massive investing ring is present, no trace of which is to found in most examples 

 of that Bpecies. There is, however, at this time no justification for claiming the 

 ident ity of ( . i ret ntricus and ( '. sol. 



The variety called ft labyrinthus by Eloper occurs al station 4505H. The peculiar 

 Bymmetiical grouping of the hexagons thai gives a strongly dotted appearance to the 

 valve is obscure when mounted in Canada balsam, bul very Btriking in the dry speci- 

 mens. Finding this in connection with large quantities of ft excentricus, I have 

 been aide to establish beyond question that this is simply a variety of the above. It 

 is given separate rank by Ralfs, Schmidt, Rattray, and De Toni. It should l>e here 

 stated that Schmidt's plate 59, figure 1 1. has uothing to do with the above forms. 



Found at Btations 2807, 2844, 2859, 3091, 3361H, 2604H, 3693H, 3694H, 2699H, 

 4023H, 1025H, 1505H, Galapagos Islands, off Kamchatka, south of Alaska, off Oregon, 

 Bering Sea. off California, and Okhotsk Sea. 



Coscinodiscus galapagensis Rati . Proc. Roy. Soc. Edinb. 16: 574. pi. .'./. 10. L889. 

 De Toni. Syll. Alg. 2: L285. L894. 



Coscinodiscus griseus galapagensis Grun.; Van Eeur. Synop. pi. 1X8. f. ,'. pi. /•-'.'. 

 /. /. L881. 



I tcinodiscus griseus Grev. ; Schmidt, Atlas pi. 58. f. 1. 1878. 



' inodvscus scintillans Grev.; Schmidt, Jahresb. Komm. Dent. Meere 2: pi. .;. 

 L8 



Coscinodiscus appolinis compacta Rati. Proc. Roy. Soc. Edinb. 16: 579. L889. 



I think Rattray is correct in making this a new species rather than a variety of 

 ft griseus Grev. Greville's species'' is quite different. 1 also thud; the form cited 

 above as ft scintillans Grev. (?). which Rattray makes subspecies compacta of ft 

 appolinis Ehrenb., is the same diatom. Indeed, the only doubl of the validity of 

 Rattray's Bpecies is its closeness to forms of ( '. scintillans Grev. I ( '. appolinis Ehrenb. >, 

 as represented in this figure of Schmidt's, rather than to forms of ft griseus. 



Found at station 2808, Galapagos Islands. 



Coscinodiscus heteroporus Ehrenb. Ber. Akad.Wiss. Berl. 1844:L > <;.">. L845. Pritch. 

 Bist. Infus. ed. 4. 831. L861. ('.run. Denkschr. Akad. Wien 48-': 74. L884. 

 Schmidt. Atlas pi. 61. f. /, ;. 6 (7?). L878. Rati. Proc. Roy. Soc. Edinb. 16: 

 540. L889. De Toni. Syll. Alg. 2: L262. L894. 

 Rattray refer- Schmidt's figured t<> ft decrescens Grun. As stated under that Bp 

 I think Schmidt is correct in assigning it here. Figure 7 is doubtful. 

 Found at station 3569H, Pribilofand Commander Islands. 



"i\. Tran-. Micr. Soc. Lond. n. s. 8: 38. pi. .'./. I .' L860. 

 b Quart. Journ. Micr. Sci. n. b. 3: 230. pi. 9.J. .. 1863. Moeb. Diat.-taf. pi. 

 L890. 



amidt, Atlas pi. 61./. 6. 



