148 BULLETIN 100, UNITED STATES NATIONAL MUSEUM 



tify the separateness of Stictodesmis; for Mastogloia's sole distinction 

 from Navicula lies in the constant dissepiments that form marginal 

 chambered rows beneath each side of the valve, and not in the fact 

 that they grow in gelatinous masses, which is equally true of some 

 other genera, including some of the Naviculae proper. 



It seems therefore that it is at least admissible to take the position 

 of De Toni and hold this genus separate from Navicula. Stictodesmis 

 australis occurs at Wake Island. All the diatoms from that locality 

 are exceptionally poor in silica; and it is noteworthy that where indi- 

 viduals appear to lack the internal dissepiment a careful examination 

 invaribly shows it to be present as an almost invisible, unsilicified 

 structure. 



Confirmatory of the foregoing, Mereschkowsky (Ann. Mag. Nat. 

 Hist., p. 415, 1901) proposes to restore the defunct genus, Olcedenia 

 Eulenstein, so as to accommodate this species ; because he finds that 

 its chromophores are totally unlike those of any known Navicula, and 

 therefore he insists that Navicula scopulorum Brebisson is generically 

 misplaced, believing that it and Stictodesmis australis are identical. 

 But afterwards (Ann. Mag. Nat. Hist., p. 32, 1902) in reviewing 

 Karsten's Diatoms of Kiel, he accepts the latter author's figures of 

 the chromatophores of Navicula scopulorum and writes they reveal 

 that N. scopulorum is valid, but nevertheless is a totally different 

 diatom from his OJcedenia scopulorum; in other words, from Stictodes- 

 mis australis. This, as above remarked, is confirmatory of the point 

 now being discussed, namely, not the validity of N. scopulorum but 

 the validity of S. australis Greville. 



As to the correct name for this genus there is more question. 

 Stictodesmis Greville and Climaconeis Grunow seem to be synonymous, 

 the latter having been published a year before the former — 1862 and 

 1863. If this is correct, Grunow's generic and specific names for 

 this diatom, Climaconeis lorenzii, would replace Greville's. Although 

 I think this view is probably right I am here retaining Greville's 

 name because of the unaccountable absence of any rhaphe in either 

 Grunow's figure or description of C. lorenzii or of his other species, 

 C. frauenfeldii the former from the eastern shore of the Adriatic, the 

 latter from the Red Sea. Nor is there an observable rhaphe in 

 specimens I have found in the fossil Marine deposit at Jackson's 

 Farm, Oamaru, New Zealand, which seem to be identical with C. 

 frauenfeldii (Oest. Diat., Wien.Verh., 1862, p. 421, pi. 7, fig. 2, and 

 pi. 8, fig. 7). How so experienced a diatomist as Grunow could leave 

 out of both figure and description a factor of such importance as he 

 knew the rhaphe to be is beyond conjecture; and as I am unable to 

 settle this point by a study of Grunow's original type, I am retaining 

 the name given in Greville's publication, where the rhaphe is clearly 

 indicated. 



