Foraminifera from. the North Sea, etc. 385 



definite oral opening, and in the absence of such the protoplasmic 

 extensions (pseudopodia) must pass through the porous cement of 

 the test. 



Many composite specimens have been found consisting of from 

 two to five individuals growing in an irregular mass. In no case, 

 however, is there any sign of a stolon tube or other connexion 

 between the individuals, their only bond of union being tlie fact 

 that two individuals have utilized the same spicule or spicules as 

 "tent-poles" for building purposes. In one instance which we 

 figure three individuals have joined together in a straight line. In 

 the absence of other evidence this specimen might easily have been 

 mistaken for a species of Ecophax. As a rule, however, the aggre- 

 gations of individuals are quite irregular in their appearance. 



The protoplasm is dark and full of rounded opaque granules of 

 secreted matter (digestion products), as in other arenaceous Fora- 

 minifera. 



We have experienced some hesitation in allotting this interesting 

 species to its genus. In spite of the selective power displayed, the 

 test is evidently of the simplest type of Ehizopod structure, and 

 the absence of a definite oral aperture combined with tbe evidence 

 which we have discovered of selective power in another unquestion- 

 able species of Psammosijhcvra (P. Boivmanni sp. n.), has guided us 

 in our decision to refer the species to the genus Psammosj^hvra. 



Psammosphcvra rustica, though never of very frequent occur- 

 rence, is met with at several of the ' Goldseeker ' stations round 

 the coast of Scotland. It occurs most frequently at Stations IX 

 and IXb in the Xorth Sea (61° 34' N. 2° 4' E., 390 metres), and 

 Stations 53 (59° 36' N. 7° W., 1000 metres), and Haul 228 (57° 59' N. 

 10° 34' W., 1600 metres) on the West Coast of Scotland, but occa- 

 sional specimens are to be met with at intermediate localities and 

 depths. 



The nearest ally of our form is apparently Rhaphuloscene conica 

 Vaughan Jennings,* described as " a tent-shaped structure, composed 

 entirely of sponge spicules." Rhaphidoscene, however, is a sessile 

 form, and the figures show that the spicules were arranged in a 

 regular cone without extensions beyond the test. It M^as described 

 from one of the 'Porcupine' dredgings, not far from 'Goldseeker' 

 Station 53. 



Psammosphmra Bovjmanni sp. n. 



Test free, monothalamous, consisting of a more or less irregularly 

 polyhedral chamber, constructed of small flakes of mica cemented 

 together at the edges by a light grey mud-like cement. Xo definite 

 oral aperture. There is often a small opening where two or three 

 of the mica plates meet at an acute angle, due to absence of cement 



* Jour. Linn. Soc, xxv., pp. 320-1, pi. x. 



