POEAMINIPEEA OF THE KBEIMBA ARCHIPELAGO. 379 



of the spicules project in a somewhat ragged fringe at the aboral extremity of the 

 shell. There is also an occasional tendency to incorporate sand-grains or mineral 

 flakes to fill up lacunse caused by the rigid nature of the spicules (figs. 22 & 25), a 

 feature that does not occur at all in K harrisii. The aperture, instead of being 

 terminal and circular, as in the type, is a terminal compressed slit or open fissure, and 

 great skill is exhibited in adjusting the spicules so as to form a finished margin, which 

 is sometimes emphasized by the building-in of a fragment of a sponge-spicule to form 

 a terminal lip (fig. 21), 



'Nouria comijressa does not occur within our experience, except at Cebu, where its 

 more widely-distributed ally N. harrisii is also found. It is noteworthy that in the 

 neighbouring Malay Seas, several species of Foraminifera exhibit a tendency to develop 

 a compressed type — for example, Bulimina elegantissima, var. compressa Millett, 

 Bulimina marginata, var. hiserialis Millett, TJvigerina auieriana, var. glabra Millett, 

 and so on. Although we are unable to account for this peculiarly local tendency to 

 form compressed varieties, we think the habit is worthy of remark. 



The few perfect specimens of Noitria compressa available for measurement show 

 great discrepancies in the relative proportions of the test. This is due to the fact that 

 any increase in the number of chambers influences the breadth of the test more than 

 the length. The smallest specimen measured -65 mm. long by -40 mm. broad. This 

 test consisted of two chambers only. The largest perfect specimen, consisting of many 

 chambers, measured 1-25 mm. long, 1-1 mm. broad. Fragments of larger individuals 

 were found. 



Slides containing the type-specimens of the genera and species described in this 

 paper have been deposited in the British Museum (Natural History) at South 

 Kensington. 



APPENDIX A. 



Report on the Mineral Constituents of the Material examined. 



By C. H. Caffyn. 



[JfoTB. — All the samples analysed represented residuum after the Foraminifera had been elutriated. The 

 percentage of carbonates shown in the analj-sis is therefore no index to the proportion of calcareous 

 material in the original dredgings.] 



Fifty grains weight of each sample was taken and passed through sieves of 30, 60, and 90 holes to 

 the inch. The portions retained by each mesh were weighed, which gives the averiige size of 

 the sand. 



VOL. XX. — PAET XII. No. 3. — November, 191-1. 3 h 



