24S roNTKlBUTIONS FROM THK NATIONAL IIERDARIUM. 



Coscinodiscus boreaUs Bail. Ain.-r. Journ. Sci. II. 22: 3. 185G. rritcli. Uisl. Tnfus. 

 (.(1. A. 838. 18G1. II. L. Smith, Sp. Diat.Typ. no. 90, 93, 95. 1874. RuU. IVoc. 

 Roy, Soc. Edinb. 16: 558. 1889. Sclimidt, Alias, p/. (^S.f. 11. 1S7S. Do Toiii, 



Svfl. Alg. 2: 1274. 1S94. 

 Co^'rinniV} Rc u s oml n s-indla Ehiviib. var.; ricvc, in Nordensk. Vega Exped. 3: 488. 



1883. Gnm. Denkschr. Akad. Wicn 48^: 77. 1884. 

 Jkvilry says, ''This rosombles C. uculus-lndis; l)ut the cellules f(jniiing the Ptar are 

 more rounded', and llie other eelluIeK aif larg<>r." llattray says, " Dif^tinguishcd from 

 C. ociiliis-iridls by the eoarser and more robust markings." The Kpeeies is neverthe- 

 less of doubtful worth; and ricve and tlninow have p.nhaps dono rightly in elassing 

 it as a A-ariety of C. ociilus4ndis. Elirenberg" gave the name to a ciuito different 



diatom, a variety of his C. radUUus. 



Found at stations 2844, 3607, 330111, Aleutian Islands and Bering 8ea. 



Coscinodiscus centralis Ehrenl). Phys. Al>h. Aka<l. \Vis.s. Herl. 1838: 129. 1840 (?); 



Bel 



/. 



/. .?). 1854. Pritc-h. Hist. Infus. e.l. 4. 828. 1838. tlreg. Trans. Roy. Soe. E.Unb. 

 21: 501. pL II. f. 49. 1857. Van Ileur. Synop. p/. 103./. H. 18SI. H. L. Sniilli, 

 Sp. Diat. Typ. no. 91, 92. 1874. Cleve k Moll, type no. 57, KM, 207, 215. Castr. 

 Rop. Vov. Chall. Bot. 2: 155. /;L 2. f. 3. 1880. Ratt. Pr(K\ Roy. Poc. Edinb. 

 16: 555. 1889. De Toni, Syll. Alg. 2: 1272. 1894. 

 Cosdnodisrtis asteromphalus Ehrent). ^ar.; Grun. Denksehr. Akad. Wien 48-': 79. 



1884. 



This species is, lik(^ the two preceding ones, too close in some of its varietit^B to 0. 

 oadus-iridis Ehrenb. In fact, we ]ia\<' here to do with a group of forms that run into 

 one another and render the specifie boundaries unsusr(>ptil)le of sharp definition. 



A fi'nire in Schmidt's Atlas ^ reijresonts the more common variety in the following 



dredging. 



^1runf)^v dors not rorogni/.e Ihis as belonging to the present speeiew; l)Ul I think 



Avilli Schmidt it should h(^ Hashed here. 



.\huiy figures of this speeies are worse than worthless, nciUihlytluit hy O'^K-ara.*^ 

 Found at Si at ion 2807, Calanagos Islands. 



Coscinodiscus cocconeiformis Schmidt, Atlas j)l 5S. f. 24-28. 1S78. Rail. Troe. 

 Roy. Soc. Edinb. 16: 590. J889. De Toni, SylL Alg. 2: i:]02. 18ab Wolh^ Diat. 



X. A. j>l. 94-/^ 4, 5. 1890. 



Th(^ forms found in the following dredging are larger than those figured by Schmidt, 

 d the dotH radiate regularly from the elliptical eenti^r, a Aariation widci' than the 

 inconseciuontial ones shown in Schmidt's ilguros, to which Rattray gives three vari- 



( (al names. 



Found at station 2807, Galapagos Islands, 



Coscinodiscus concavus (Ehrenb.) dreg. Trans. Roy. Soe. Edinl>. 21: 500. 2^?. W.f, 

 47, 1857. Cleve, Rih, Sv. Vet. Ahad. Ilandl. 1^': ^. 1873. Ehrenb. IMiys. Abh. 

 Aka<l. Wiss. Berlin 1841: 112. 1843; P>er. Akad. AViss. Rerl. 1844: 78. 1845; 

 Mikrog. pi kL /. 4 (not pi IS. f. SS). 1854; Phys. Abh. Akad. ^Viss. Derlin 

 1871: 2G0. 1873. Schmidt, Atlas, pi G2.J. S (not pi 59, f. 16). 1878. Ktit/. Sp. 

 Alg- 125. 1849, Ratt. Proo, Roy. Soc. Edinb.' 16: 469. 1SS9. De Toni, Syll. Alg. 



2: 1215. 1894. 

 Coscinodisais conravfis africac Ehrenb. Ber. Akad. Wiss. Berl. 1844: 79. 1845. 



an 



aBvw Akad. Wiss. Berlin 1861: 294. 1862. 



^ Schmidt, Atlas;)?. CO.f. 12. 1878. 



cProc. Roy. Irish Acad. II. 2: pi 2G,f, 19.1^7b. 



