56 BEV. E. o'MEARA ON THE DIATOMACEOUS 



the costae appearing as a narrow band of puncta. On side view 

 rhombic ; costse very fine, previous. 



No. 6. Marine, from surface of the water between Kerguelen 

 and Herd Island. This is a very remarkable gathering, consisting, 

 for the most part, of various species of Ch&toceros with spines of 

 extraordinary length aggregated in small, masses of jelly-like ap- 

 pearance. In every instance the spines were broken off from the 

 valves ; so that it was difficult in many cases to ascertain the spe- 

 cies; however, Chcetoceros peruvianus, Bright, and 0. borealis, 

 Bail., were unmistakably present, and that in profusion. These 

 species constituted by far the greater portion of the material ; and 

 mixed with them were found some specimens of Hemiaulus an- 

 tarcticus, Ehr., Bhizosolenia calyptra, Ehr., H. styliformis, Bright, 

 M. imbricata, Bright, and JR. setigera, Bright. 



Fragments of what appears to be an undescribed species of 

 Hhabdonema occurred in great number ; but although it would be 

 remiss to omit reference to this form, the description cannot be re- 

 garded otherwise than as unsatisfactory. It was difficult to obtain 

 a side view of the frustules ; and when a filament was turned so 

 as to bring the side view under observation, it appeared as if the 

 valves had been detached from it. All that could be learned con- 

 cerning these latter was that they must be circular or nearly so. 

 Some few forms were found that seemed likely to correspond ; 

 they were ring-like, strongly costate ; and in one or two cases I 

 noticed specimens in which the central part was fractured, show- 

 ing that what otherwise would have been considered a rii 

 really a continuous disk ; possibly these may be the side view of 

 the valve, which, if so, must be described as plain and destitute of 

 striae except at the margin. Three other forms appeared which 

 seem not to have been previously described. 





Gomphonema antarcticum. Marine. PI. I. fig. 3. 



Frustules "0022 in length. On front view cuneate, linear. Ou side 

 view greatly wider at the upper than the lower end, euneate ; striae 

 fine, linear, slightly radiate, and interrupted in the middle by a narrow 

 longitudinal unstriate band. 



Terebraria kerguelensis. Marine. PL I. fig. 4. 



Frustules united in a filament, adhering in pairs which present a lenti- 

 cular outline ; the striae appearing, on the front view, in the form of 

 large marginal puneta. Valves, on the side view eliiptical-lanctolate ; 

 length '0028 : breadth 0005 ; striae moniliform, parallel, pervious. 



