March 1, 1870.] 



HARDWICKE'S SCIENCE-GOSSIP. 



61 



NEW DIATOMS. 



A DESCRIPTION and figures of sonic of the 

 -*-*- Diatomaceous forms obtained during the 

 voyage of the Imperial Austrian frigate Novara, 

 extracted from Herr Grunow's work,* may be ac- 

 ceptable to the readers of Science -Gossip. I 

 have therefore selected the following as the most 

 interesting. 



1. " Cllmacodlum, Grim. — Frustules smooth, 

 scarcely siliceous; ends more or less enlarged, 

 truncate, forming a lengthened filament. 



" Cllmacodlvm Erauenfeldlanum — Characters that 

 of the genus. In floating masses on the sea near 

 Telangshong (fig.' 58). A very remarkable genus; 

 the frustules are slightly siliceous; it is possibly 

 related to Eucampia zodiacus. I know no diatom 

 which can be better compared to a ladder than this. 

 I have therefore given it the above generic name." 

 (Judging from Herr Grunow's figure, I am inclined 



/v v v vv\ 



Fig;. 5S. Climacodium Frauenfeldianum, x 100. 



to doubt the diatomaceous nature of the organism ; 

 the absence of a connecting zone, so important a 

 feature in the diatomaceous frustule, renders its 

 position in the class Liatomaceee very dubious.) 



2. " Pleurosigma valla hint, var. nicobaricum, Gru- 

 now. — Valve lanceolate, ends slightly obtuse, median 

 line straight, nodule slightly dilated (transversely), 

 stria? oblique, 40 to 44 in '001"; in ' Polycystin stone ' 

 {Polycistin Gesteln), island of Nankoori (fig. 59). 

 It is probably related to my P. glganteum, but is 

 smaller, shorter, and has less obtuse ends. The 

 transverse stria 1 are somewhat stronger than the 

 oblique, which, as they approach the ends, become 

 somewhat more oblique." (The Pleurosigma vali- 

 dum of Shadbolt is identical with P. rlgldum of the 

 Synopsis. The variety figured by Herr Grunow is 

 not uncommon. I have it in a gathering from the 

 Erench side of the Channel, Corsica, Jaffa, and the 

 West Indies. The increasing obliquity of the 

 striae as they approach the ends is produced by 

 the "increased pitch" of the valve on either side 

 of the median line, as it approaches the apices: 

 a transverse section in the middle would be 

 an obtuse, that at or near the ends an acute, 

 angle.) 



3. Stictodiscus californicus, var. nankoorensis, 

 Grunow. — Valve with radiating and anastomosing 

 costae, the spaces between the costa: with a single 

 row of conspicuous granules. Occasionally in the 

 " Polycystin stone" from Nankoori (fig. 60). Like 

 Greville's species, a row of puncta is placed between 

 two costse. The costa; divide in various ways as 

 they approach the circumference, and the puncta 

 are consequently more numerous. The puncta on 

 the central portion of the disc are arranged in an 

 irregular network, from which the marginal costa: 

 proceed : the same may possibly be found in the 

 California!! species. 



/ 1 



Fig. 39. Pleurosigma validum, var. nicobaricum, x 400. 



4. AchiutntJics inflata, Grunow = A. ventrlcosa, Ehr. 

 {nee. Kutzing) = Stauronels inflata, Kutzing, "Bacil- 

 larieii " Eossil Deposit. Tahiti, Java.* Although 

 not a new form, and its occurrence merely noticed 

 by Herr Grunow, I give a figure and description 



* " Reise seiner Majestat Fregatte Novara urn die Erde." 

 Botanischer Theil. 1 Band : Algen. Bearbeitet von A. 

 Grunow. 



Fig. 60. Stictodiscus californicus, vax.niuikoorensis, x 500. 



: of it, as I have found it sparingly in sonic moss 

 from a marsh near Norwich. I must differ from 



* Essbare Erde. 



