262 CONTRliiUTKJNS PKOM THK NATIONAL HKHHAHIUM* 



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Actinocyclus (?) elongatus Gnin.; Van Hour. Synop. pL rJ5.f, /.5, 77. 1H81. 



I am in luiniiuny with Van lleurrk in doubting the corroctnos.s of calling this an 

 Actinocycluis. Not only the extrenio contraHt of this elongated form with any known 

 Ai:tinocychis (my upecimcMi iw twenty times as lung as wide), but th<' absence of any 

 true paeudonoduh' mnkes thip classifieation uuLsati^^factory. In iny specimen at least, 

 the dot which (rrunow considers a pseudonodidc is only an enlarged l)cad on the upper 

 surface of th<^ valv(% and lacks the sliimnn^ring app<nirance of Iho true p^eudonodule. 

 In my form also, as in Van Ileurck's figures, thvre are tw^o such, located at short dis- 

 tances from the two ends. Rattray^' stati'S that tlie pseudonodule is genuine in a 

 Tuscarora valve, but doul>ts its genuineness in another subspecies which Grunow fur 

 that reason names A, elonyatus dabiaJ> Tln'fact is, we have liere another illustration 

 of the difTiculfy of considering Actinocyclus anything more tluin a subg<^iuis of Cos- 

 cinodiscus. Compan* the figures of Van Heurck ^^ witli lliat of Ihm-inodm'UR eJongatus 

 (Irun. in (igur(^ 14 of the same plate. 



Found at stati<in 21)11), off the coast of southern California. 



Actinocyclus interpunctatus (Briglit.) llalfs in Pritch^ Hist. Infus. ed. 1. 835, 18G1. 



Ratt. Journ. Quek. Micr. Club 11. 4: 20;b 1890. (Not 11. L. Smith typ. no. 12,) 

 Acllnopfychia^ tiUerpandalus Bright. Quart. Journ. Micr. Sc-i. 8: 1)1. pl.G.f.ll. 18G0. 

 Hyaloiliscus sleU'Kjtr Wd'il. err. det. Moll. Amer. .lourn. Micr. 2: 100. 1877. 

 Eupodisciis {Actinopfychus) inLa'pu;nviaias Uriglit.; Grun. Amer. Journ. Micr. 8: 



101-102. 187S. 



The above is i)erhaps a l>road varit^fy (jf .1. raljsii (W. Smith) Ridfs, and diffi^rs little 

 fnmi A. sparsus (Greg.) Ratt. The slide in 11. L. Smith's type no. 12, bearing the 

 above name and i(U'ntical with his slide 421, marked ^^Podosira majyiitta Grun.," is 

 better considered a variety of A. raJfsii^ that is, if that species and this one are to be 

 kept separate. Rail's was himself dtuilil ful about this form being a valid sj)ecies, I 

 share tliis doubt. Still, as there is ground for question on this point, it is perhaps 

 best to acc(^pt Rattray's decision and retain the above name. 



Found at station 1505I[. 



Actinocyclus niinutus Grev.; Ratt. Journ. Qu(dv. Micr. Club II. 4: 170. pi. 11. J. 4- 



-i *-» ^^ ^ 



ISVHh 



The original specimens came from Manila; this one from tlic Cialai)ngos IsLuuls. 

 Found at station 2807, Galaf)agos I^^lands. 



Actinocyclus oliverianus (VMcara, Jour. Linn. Soc. Rot. 15; 58. pi. Lf. 7. 187() (?). 



Castr. Rep. Voy. Chall. Bot. 2: 115. pi 4 J- 7. 1886. RiUt. Journ. Quek. Micr. 



Club 11. 4: 148. 1890, 

 Podosira olivcriana Grun,; Van IT(mr. Kynop. pi. llS.f.5. 18S1. 

 Micro podiscus oliverian}is Grun.; Van lleur. Synop. pL llH.f. '). I8SI; Denkschr. 



Akad. Wien 48': 70. 1884. 

 Aciinocycliis umbonal us Ca&tr. Rep. A'"oy. Chalk l>ot. 2: 145. pl.4-f- i- 188(1. 



It is difhcult to decide on the genus of this diatom. It has the shuumering pseudo- 

 nodule of Actinocyclus, the watch-case milbng of Podosira and the general border of 

 Craspedodiscus. I place it as above because rny form, unlike that figured by Van 

 Heurck and the one referred to by Rattray, lias a true pseudonoduh*, a large, hyaline, 

 refractive globule, and not the small process of Van Heurck'w and Rattray's figures. 

 The view of Van Heurck and of Grunow, who looked on this as a species of Podosira, 

 does not seem to me to be tenable. It may b<^ foun<l necessary to adopt Grunow's sug- 



f^ Journ. Quek. :Micr. (Jul> II. 4: 107. 1890. 

 ?> Van Ileur. Synop. pi. 1:^5./. 16 17, 1881. 



