OF THE KERGUELEN REGION OF THE GREAT SOUTHERN OCEAN. 



475 



Cord/uvn splendent, Rattray. 

 Hemiaulus antarcticus, Ehrenberg. 

 Adinocydus oliverianus, O'Meara. 



,, „ forma minor. 



AsterompTialus brookei, Bailey. 



,, liookerii, Ehrenberg. 



Baderiadrum varians, Lauder. 

 Goscinodisms africanus, Janisch, var. wallichiana, 

 Grunow. 



,, anguste-Uneatus, A. Schmidt. 



,, convexus, A. Schmidt. 



Coscinodiscus denarius, A. Schmidt. 

 ,, excentricus, Ehrenberg. 



„ kutzinyii, A, Schmidt, var. glacialis, 



Grunow. 

 ,, lentiginosus, Janisch. 



,, lineatus, Ehrenberg. 



,, lunie, Ehrenberg. 



„ marrjaritaceus, Castracane. 



,, qculus-iridis, Ehrenberg. 



,, subtilis, Ehrenberg. 



tumidus, Janisch. 



LIST IX c. 



The following 26 species occur both in the surface gatherings and in the deposits at 



the bottom within this region : — 



Navicula aspera. 

 „ subtilis. 

 Synedra lanceohda. 

 Thalassiothrix longissima. 

 Trachgsphenia australis. 

 Fragilaria (?) an Terebraria (?) sp. 

 Rhir.osolenia setigera. 



„ styliformis. 



Melosira sp. (?). 

 Corethron criophilum. 

 Hemiaulus antarcticus. 

 Actinocyclus oliverian us. 

 Astcromphalus brookei. 



Asteromphalus hookerii. 



Coscinodiscus african us. 



„ convexus. 



„ denarius. 



„ excentricus. 



„ lutdngii. 



„ lentiginosus. 



„ lineatus. 



,, lunw. 



„ margaritaceus. 



„ oculus-iridis. 



., subtilis. 



„ tumidus. 



The following general remarks on the Diatoms observed in the surface gatherings and in the deposit from the 

 Challenger deep-water Station 157, extracted from the Challenger Report, Summary of Results, pp. 513-514, may 

 he of interest : — 



Considerable differences are recognisable between the general appearance of Diatom preparations made from 

 surface gatherings as contrasted with those procured from the ooze forming the bottom in this locality. By far the 

 most abundant form at the surface was the peculiar, very elongated, flexuous Thalassiothrix longissima, var. antarctica, 

 (Jleve and Grunow [ = Synedra thalassiothrix, Cleve in parte], a species which has already been recorded as forming 

 large floating masses in the Arctic Ocean. 1 In the Antarctic its frustules were found arranged in little bundles — from 

 ten to twelve together — fastened together loosely at one end, but separate at the other, the whole being loosely twisted 

 into a spindle. In preparations isolated frustules of it occur but rarely, often two are found closely apposed, but not 

 uncommonly three, four, or even more are so placed. It is, perhaps, with Chcdoceros remotum, Cleve and Grunow 

 [= C. janischianum, Castracane], the most characteristic species found on the surface. 



The Chsetocerotidse and Rhizosolenite are abundantly represented in the surface waters, but they are only repre- 

 sented by the terminal calyptra? of the latter in the bottom ooze. Most of the delicately curved, though often large, 

 forms, of Corethron, and the singular cylindrical Dactijliosolen, have only been found in surface gatherings, whilst the 

 remarkable Trachgsphenia australis, Petit, var. antarctica (Schwarz) [ = Fragilaria antarctica, Castracane], which abounds 

 in the ooze, is much less common in the surface gatherings. Frustules of Coscinodisci and Actinocycli are also much 

 less numerous at the surface than upon the bottom, but no species which is present in the superficial waters is absent 

 from the ooze. 



The contents of the alimentary canals of several of the Eehinoderms and Annelids were examined with the view 

 of ascertaining whether or not a predilection was exhibited by the animals for any particular species of Diatoms ; it 

 was found, however, that they made use of the ooze as a whole, in all probability taking in the immediate surface 

 layer containing specimens recently fallen from the surface, which, doubtless, still contained some organic matter. 

 The tubes of the Annelids, and the test of the Foraminifera Eeophax nodulosa, contained many of the large Coscinodisci 

 which would appear to have been to a greater extent selected than the others in the deposit. 



1 Bihan-j til K. Svensl: Vetensk. Akad. Handl., Bel. i., No. 13, Stockholm 1873. 



