204 Mr. H. J. Carter on a new Genus 



rule, the " pseudopodia " come from the great aperture at the 

 end of the test in his figures — although of course, where 

 there is a canal-system, they inay issue also from its open- 

 ings wherever these may be, either along the course of the 

 septa or on the marginal cord as in Operculina. 



The ferruginous colour, however, which pervades the test 

 of Lituola canariensis is so much like that of the dried sarcode 

 lining its cavities, while the test itself is composed of a hetero- 

 geneous assemblage of sand particles, fragments of siliceous 

 sponge-spicules, &c., of different sizes, varying from im- 

 measurable minuteness to large grains which may be seen 

 with the naked eye, that it is not extraordinary that the pores 

 of the " labyrinthic " canals, which probably are not larger 

 than those of the Nummulitida, viz. about l-20,000th inch in 

 diameter (in Operculina arahica)^ should, under the circum- 

 stances, not be visible among the heterogeneously composed 

 surface of L. canariensis^ — where there is no tubulation to lead 

 to them, the minute passages into which they open must neces- 

 sarily be crooked from the coarse arenaceous material, as before 

 stated, through which they pass, and they can only be sought 

 for amidst the minute particles of the cementing sand by 

 reflected light, — when they are but just visible on the surface of 

 Operculina^ where the structure is homogeneous and trans- 

 lucent, there is a tubulation to lead to them, their courses 

 respectively are straight, and they can be sought for in the 

 centres of the tubes respectively by transmitted light. 



One of these obstacles, however, is got rid of in Bdelloidina 

 aggregata by the-materials of which the test of this species is 

 composed being almost colourless, and therefore without the fer- 

 ruginous tint that exists in Lituola ; hence the ultimate extent 

 towards the surface of the dried sarcode lining the " laby- 

 rinthic " canals can, by its dark brown colour, in the vertical 

 section be distinctly seen and measured by the microscope, so 

 far as a " point " can be measured. But even here direct 

 observation of the surface does not enable us to recognize the 

 pores of the " labyrinthic " canals, because the dark point 

 which appears to be the sarcodic lining of the pore is re- 

 tracted, and there can be nothing left but the bare crevice 

 among the minute particles of which the cementing sand is 

 composed to indicate the opening through which it was pro- 

 jected — although in the vertical section, where a lateral view 

 of the "labyrinthic" canal can be obtained, the proximity of 

 the point is distinctly seen so near the surface that it can hardly 

 be doubted that it once opened there (fig. 7, e). 



I therefore must demur to the tests of the Lituolida being 

 regarded as " imperforate," and place myself on the side of 



