288 DISCOVERY REPORTS 



Cells rectangular, almost square, united to form long flat ribbon-like chains, twisted 

 about the pervalvar axis. Adjacent valves adhering closely, leaving no aperture. Valve 

 linear in outline, valve surface often showing a small prominence which fits into a corre- 

 sponding depression upon the neighbouring cell. Chromatophores : numerous small 

 rounded bodies, which are arranged in a number of lines radiating from the central 

 nucleus. Cells very weakly siliceous, completely soluble in mineral acids and absorbing 

 dyes readily. Polar axis of cell 8o-ioo/x ; pervalvar axis 90-120^. 



A neritic species, having a wide distribution in temperate and subpolar seas. It was 

 observed frequently in the Peru Current material. 



Observed at Sts. WS 709, 710. 



Family ANAULACEAE 

 Subfamily ANAULOIDEAE 



Genus Anaulus Ehrenberg 

 Ehrenberg, 18446 



The exact position of this genus is very uncertain. The bipolarity of the cells suggests 

 relationship with the Biddulphiaceae, particularly with the genera Eucampia and Eunoto- 

 gramma, but the entire absence of surface spines and the loculate valve surface have 

 prompted systematists to separate them. I have placed the Anaulaceae immediately 

 after the Eucampioideae, between it and the Chaetoceraceae ; to the latter it bears no 

 resemblance except of course in the bipolarity of the cell. Microspores and resting 

 spores are unknown in Anaulus. The genus has been placed by some authors immedi- 

 ately preceding the Araphidineae, but in the systematic arrangement I have adopted, 

 this course would bring Anaulus next to Corethron to which it bears no relationship 

 whatever. It is very doubtful whether a separate family is necessary for this genus, but 

 in view of the uncertainty which exists concerning its exact relationship to the genera of 

 the Biddulphiaceae this course seems preferable. 



The genus is neritic ; the cells, united by means of mucous pads, are usually epiphytic 

 on larger algae. The genus is distributed in both warm and cold water. 



Anaulus ellipticus Hendey, sp.nov. (PI. IX, figs. 4-13.) 



Frustulis in catenis 3-8 conjunctis, e facie connectivali visis rectangularibus ; cingulis 

 multiplicibus ; valvis ellipticis vel late ovalibus, superficie lenissime convexa; septis 

 validis 2-6, in marginem crassam confluentibus ; punctis subtilissimis, in lineis sub- 

 radiantibus in medio dispositis, alibi irregularibus. 



Mensura valvarum 70-110 x 35-50^. 



Hab. in aquis marinis "Bransfield Strait", prope insulam "Astrolabe" dictam, in 

 oceano Antarctica. 



Typus in Herb. Mus. Brit. No. 33962. 



A meroplanktonic species associated with Anaulus scalaris, from the Bransfield Strait. 

 It is much smaller than that species and different in outline. Repeated attempts to 



