rOEAMIJS^FEEA OF THE KERIMBA ARCHIPELAGO. 553 



perforated at its two extremities, as shown in Brady's figs. 16, 17, a feature which is 

 more commonly observed in the species S. acutimargo. At Stn. 11 the costae in a few 

 specimens were produced into broad ribs. 



In many of the Kerimba specimens tlie costae are obliquely set or even undose ; this 

 variety passes gradually into S. foveolata. 



15. Spiroloculina foveolata Egger. 



Spiroloculina foveolata Egger, 1893, FG. p. 224, pi. i. figs. 33, 34. 



„ nitida (reticulate variety) Millett, 1898, etc., FM. 1898, p. 266. 



„ foveolata Heron-Allen & Earland, 1908, etc., SB. 1909, p. 311, pi. xv. fig. 2. 



„ nitida, var. foveolata Chapman, 1900, FLF. p. 171, pi. xix. fig. 4. 



7 Stations. 



Typical specimens are rare in the dredgings, but occur occasionally at many Stns. 

 There is a great range in the nature of their markings, some being regularly reti- 

 culate, while others are, in strictness, merely specimens of 8. grata in which adjacent 

 sulci have beeome fused together at irregular intervals. 



16. Spiroloculina limbata d'Orbigny. (Pi. XL. figs. 14-17.) 



'' Frumentaria Sigma et Rhombos " Soldani, 1798, Testaceograpliia, vol. ii. p. 54, pi. xix. fig. m. 

 Spiroloculina limbata d'Orbigny, 1826, TMC. p. 299. no. 12. 



Parker, Jones, & Brady, 1859, etc., NF. 1871, p. 248, pi. viii. fig. 22. 

 „ excavata Jones, Parker, & Brady, 1866, etc., MFC. 1895, p. 107. 



13 Stations. 



The Soldanian figure selected by d'Orbigny as the type of his species S. limhata 

 represents an excavate Spiroloculina of a particularly well-marked type, which is one 

 of the characteristic forms of the Kerimba dredgings. Regularly oval in shape, with 

 a short produced neck, and bilaterally concave in section, it consists of four to six pairs 

 of inflated chambers with excavate sutural lines. The peripheral edges are highly 

 convex, the highest point of each chamber being oil its inner edge, where it dips 

 sharply down into the sutural depression between the two chambers. Occasionally 

 the chambers are rounder in section, so that a sectional view of the shell shows a series 

 of rounded curves. This round-chambered form represents the transition towards 

 S, nitida ; d'Orbigny's species S. limlata may, in fact, be regarded as intermediate 

 between his S. excavata and his S. nitida. The surface of the test in the Kerimba 

 specimens is always rather rough and unpolished. S. limbata occurs at most Stns., 

 generally in considerable numbers, the best being at Stn. 12. At Stns. 2a, 6, and 7 it 

 passes gradually into *S'. nitida. At Stn. 13 it passes gradually into S. excavata by the 

 flattening of the peripheral margins. 



Specimens range between "7 and I'l mm. in length, 'S-l'D mm. in breadth, and 

 •3-'5 mm. in thickness of final chamber. 



4 k 2 



