293 HENRY B. BRADY. 



of the shell as minute, cylindrical projections from the 

 surface.-^ Without departing from an attitude of caution in 

 accepting evidence upon a subject so beset with difficulty, I 

 will endeavour in a few words to summarise the facts bearing 

 upon it, chiefly on those concerning the two genera 

 Glohigerina and Pulujiulina. 



1. We have positive evidence that Foraminifera do live at 

 the bottom of the deep sea, from the common occurrence at 

 great depths of certain forms with composite or arenacous 

 tests ; and we have negative evidence in the same direction 

 in the entire absence from the surface fauna of many hyaline 

 genera, which are abundant in bottom dredgings. 



2. Both in Pulvinulina and Glohigerma (but notably in 

 FulvimdincC) species closely allied to the surface forms are 

 common in the bottom ooze, though they never occur at the 

 surface; amongst others, Glohigerma dubia and Gl.digitata, 

 Pidmmdina elegans, P. Karsteni, P.pauperata, and P.favns. 

 Hence there is no d priori improbability that the other 

 members of the same genera are capable of supporting life at 

 the bottom. 



3. A comparison of specimens of the same species, taken 

 at the surface and at the bottom, demonstrates at least that 

 the average size of the former is less than of the latter, and 

 that the thickness of the shell-wall of the largest surface 

 sj^ecimens bears no comparison with that of adult bottom 

 specimens. 



4. Nothing comparable to the thick-shelled Orbidi?}^?, 

 still less to those with tests composed of several layers, is to 

 be met with in the surface fauna. 



5. No surface Glohigerince have hitherto been obtained by 

 means of the towing net from points on our own shores at 

 which they are found at the bottom. 



6. A fact adduced by Dr. Wallich, of some weight, as I 

 think, namely, that Glohigerina shells are found in the 



^ I find a uote of Dr. Wallich's, iu a lecture delivered before the iloyal 

 Institution, in 1S61, the substance of which appeared, I believe, in one of 

 his earlier papers, which is quite iu accordance with these results. Speak- 

 ing of a particularly pure Glohigerina deposit he says : — " The specimens 

 from the immediate surface stratum of the sea-bed alone retained their 

 normal appearances, both as regards the perfect state of the sarcodic 

 contents of the shells and the presence of the pseudopodia. The latter 

 . organs were never seen by me in an extended position, but in the specimens 

 alluded to, and in those only, the pseudopodia occurred as minute bosses, 

 res(^mbling in shape the rounded rivet heads on boilers, closely adpressed to 

 the external surface of the shell." 



