272 Transactions of the Society. 



X. — Oil some Foraminifera from the North S(a, etc., dredged hi/ 

 the Fisheries Cruiser ' Goldseeker ' [International North 

 Sea Investigations — Scotland). Ill On Gomuspira 

 diffusa, a new type from the North Sea. 



By Edward Heron-Allen, F.L.S. F.G.S. F.E.M.S., 

 and Arthur Earland, F.E.M.S. 



{Read May 21, 1913.) 

 Plate XII. 



Cornuspira foliacea Philippi sp. (''inoustrous specimen"). Brady, 1884, 



Foram. ' Challenger,' pi. xi, fig. 7 (no reference in the text). 

 Ditto. Ehumbler, 1903, System. Znsanma. d. recent. Rhizopoden, Arch. 

 Protistenk., iii. p. 287, fig. 1416. 



Description of Species. — Test free, porcellanous, of extremely 

 variable form and size, constructed of a non-septate calcareous 

 tube which apparently is at first coiled in a plane compressed 

 spiral of rapidly increasing width (type of C. foliacea Philippi sp.), 

 and subsequently abandons the spiral mode of growth, becoming 

 protean. It may then adopt one or other of two different plans 

 of increase. 



1. The tube may spread out in a flattened irregular sheet, the 

 aperture extending the full width of the test, round the marginal 

 edge, as in C. striolata Brady ; or 



2. The tube may divide into from two to five separate and 

 divergent tubes, each o^ which may in turn subdivide again. Very 

 rarely after division the tubes may rejoin and become fused into 

 a sin^de tube a^^^ain. 



3. In rare instances the shell proceeds in its growth by a 

 comljination of the first and second scheme, i.e. after growing in a 

 flattened sheet it proceeds to constrict itself along the apertural 

 edge, and to ramify from these points. 



The walls of the test are very thin and extremely fragile ; 

 the surface is irregular, and constricted at frequent intervals with 

 curving furrows or depressions of varying depth and breadth, 

 resembling in external appearance sutural lines. These constric- 

 tions apparently mark stages of growth in the life-history of the 

 shell. They are not mere surface markings, being as clearly 

 indicated inside the tube as on the surface. They may be com- 



