966 CONTRIBUTION'S K1{(»M THE NATTONAJ. IIERBARIUM. 



DUcoplea sinensis l^hrcnl). Mikrog. pi 39. Lf. 10, pi S9. II, f. 30. 1854. 



Discoplca aihmllca Elirenb. ^^likrog. pi 19. U.J. 29. 1854. 



Cydotdla dallasiana ^\ Siiiilli, Syiiop. Crit. Diat. 2:87. 1856. Ral.li. Fl. Eur. 



Alg. 1: ?^?>, ]8()4 (not 11. L. Riiiilh. Sp. Diat. Typ. no. 102. 1874). 

 CyclotfUa s^Wr^'?^9 Ralfs in Prilcli. Hist. Infus. cd. 4. 812. pi 15. f. 4- 1801. 

 CydoteUa allantira Ralfs in rrildi. Hist. Infu?. e(L 4. 812. pi 15. f. 3. ISGl. 

 Cydotdla nvihigna Grun. in ( hwo. & Grnn. Sv.Vet, Akad. Handl. 17'-; 119. pi 7, 



/. 133. 1880. Dc Toni, Syll. Alg. 2: 1352. 1894. 



Though Ihvrv. is KLUiilarity butwiu^n tliis and C. sUjloruni l^right., I do not think it is 

 suflicionl to nocossitato uniting thoni, as is done l>y Di: Toni.f* They are h<jld as sei)a- 

 rate by Rails, Sclinudt^andVanncurck. Tlioroiw no doubt about C. Hinenm{YA\Y KMih.) 

 Ralfw being this species; though Dlsroplm sinensis Elirenb., on which KliUs biuses his 

 name, is f^onK^what (piestionable. Tlie.^anie is 1ru(» of (\ dalhisinna W. Smith, Avliicli 

 from the meag(*r description and the absence of anj' ilUistralion is rather indefinite. 

 H. L. Smith's type no. 102 is a typical C. stylonnn ihight,j to which, llierefore, if the 

 two an! to bo held separate, it slujuhl ho referred. 



Found at wtaliojis 208811, 451(111, off California and in Gulf of California. 



CycloteUa stylorum Ibiglit. Quart. Journ. Miu-. Si-i. 8: 90. pi 6.f. !(l. 1860. Van 

 Hour. Synop. pi 92. f. 2-5. I88t Schmidt, AUas pi 223. f. (IS, 1.890. Trilch 

 Hist. Infus. cfb 4. 8i:5. 1801. Moeb. Diat.-taf. pi 29. J. 16. 1890. 

 CyeJoldIa (hiUfwana W. RmitlK (Tr. det. 11. L. Smith, Sp. Diat. Typ. no. 102. 1874. 



Art only a single valve was found the identihcat ion is somewhat doubtful. f(tr witliou"' 

 a complete frustuh^ it is nearly im|)ossibh; to (kicith^ beLween the above species and 

 yimilarly constructed valves of ^b4t)sira,as, for exam])]e, those of M. suhornata Sclnnidt. 



Found at station 3203H, soutli of Ah'utian Islands. 



HEMIPTYCHUS Elirenb. 



Eemipfychns Ehrenb. \Wr. Akad. Wiss. Berb 1848: 7. 1849. 



Arachno(lisr)!sW:i\\. Ber. Akad. ^^■i.ss. Berl. 1849: Ob 1850; in Wilkes U. S. Explor. 



Exped. 17: 174. 1874. l)e Toni, Syll. Alg. 2: 1311. 1894. 

 Aradmoidiscus Deano; Pritch. Hist. Animalc. ed. 2. 318. 1852; Hist. Infus. ed. 4. 



841. pi 15. f. 18-21. ISOl. 11. L. Smith, The L(^ns 1: 19, 93. 1872. 

 Aradinoidiscus JS'iiW . \ ^V. Smith, Syn(j}). Brit. Dial. 1; 25. pi 31. f. 256. 1S53. Deane, 



Quart. Journ. ilicr. Sci. 6: 188. 1S5S. 



The al)ove nam(^ must take preced(^nce over AiiK^inodiscus, which was finst pub- 

 lished in 1850j Ehr(Mil)(ng crediting the name to J. \\\ Iknh^y, who probably commu- 

 nicated the name in a letter In Fhrenberg, as no iviM'o of it can be found in J^ailey's 

 earlier writings. In 1850 ElireTd)erg discards ihc^ earlier name, in consequence of its 

 prior application to a genus of insects, and adfipts the very appropriate and descrip- 

 tive name of Arachnodiscus, which was first used in England by II. Deane (spelling it, 

 however, as it is nt>w generally spelled, Arachnoidiscus) in an unpublished paper read 

 before the Microscopical Society of London on March 17, 1817. 'J 



Ehreid^erg's excuse for abandoning his earlier name, Ilemiptyt4uis, is not valid. I 

 think it is both unnecessary and unwise to duplicate names in botany and zoology, 

 and especially so where the forms are, as with the diatoms, close to the dividing line 

 between the two kingdoms. But in this instance th<T(^ is no duplication; the hemii>- 

 terous name previously eslablislu^l by Germar in 1833* being Ilemiptycha, not 



«DeToni, Syll. Alg. 2: 1352. 1894. 

 ^ Quart. Journ. Micr. Sci. 6: 188. 1858. 

 cSilb. Rev. Ent. 1833. 



