1883.J 



On Syringammina. 



159 



One of the specimens rolled out of the oozy layer of the deposit 

 when the dredge was emptied on the deck and broke, unfortunately, 

 in the hands of the sailor who lifted it; the other was found on 

 passing the mud through the sieves, and when first observed 

 appeared quite spherical." 



I learn that a somewhat similar specimen was dredged at a depth 

 of 1000 fathoms off the Azores, during the "Challenger" cruise, 

 but that it wenb to pieces in the sieve.* 



A few words must be added respecting the zoological position 

 and affinities of the new genus. On the whole, Syringammina finds 

 its nearest allies, so far as living Foraminifera are concerned, in the 

 deep-sea varieties of Astrorhiza. Comparing it with Astrorhiza 

 arenaria,\ its investing walls are found to be constructed in precisely 

 the same way of loosely aggregated sand, and even in the size of the 

 grains there is great similarity, though this may be in a measure 

 accidental. But whereas the test of Astrorhiza consists (typically) 

 of a few tubes, generally unbranched, radiating on one plane from 

 a central cavity or chamber, that of Syringammina is formed of 

 a multitude of tubes which radiate nearly equally in all directions, 

 and have numerous branches which inosculate freely. In Astrorhiza, 

 as in Syringammina, the peripheral ends of the tubes serve as the 

 general aperture ; and in both the orifices are masked by aggregations 

 of loose sand, forming rounded and apparently closed terminations. 



The genus Parkeria has already been referred to in describing the 

 mode of increase by concentric layers, and both in size and general 

 contour there is considerable resemblance between Syringammina and 

 the fossil type. But the similarity of internal structure, apparent on 

 a comparison of some of the drawings now furnished, with the 

 illustrations accompanying the original memoir on Parheria and 

 Loftusia^X is much more remarkable and cannot be passed over with- 

 out notice. Owing to the difference in the magnifying powers 

 employed, the resemblance in the drawings is more striking than in 



* It may be of service to those who have the opportunity of dredging, to note 

 that the sandy skeletons of organisms of this sort may be sufficiently strengthened 

 to bear handling by placing the specimens for a time in strong alcohol, and then 

 drying ; afterwards, when thoroughly dry, saturating with a very dilute solution of 

 dammar in benzole, and draining on blotting-paper. The dammar solution should 

 be so weak that it does not leave a gloss on the surface of the specimen when 

 finished. 



f M. Sars, Carpenter, and Norman assign these deep-sea sandy forms to the 

 same genus as the shallow- water organism, Astrorhiza limicola, which has a chitinous 

 investment, coated with soft mud. I have not disturbed the arrangement, but my 

 impression is that they represent two distinct genera. 



X " Phil. Trans.," 1869. Compare for example the structure of Syringammina as 

 shown in figs. 6, 7 of the present paper with that of Parkeria and Lqftusia as 

 represented in some of the figures in Plates 73 and 79 of the memoir referred to. 



