Dr. .1. D. Macdoiuild on t/i> Pnlyoy.^tinM. L>2'i 



Notwithstanding the evidence of excellent (»bservers as to 

 the pseudopodia and tlie locomotive properties of genuine 

 Foraniinifera, I can only say that, having from time to time 

 submitted thousands of the living animals to close inspection, 

 I have seen no evidence <»f the existence of j)seud(tpodia, and 

 perfect fixity has been the rule, either by a broad base or a 

 petjicle. Indeed tiie place of attachment of the hitter is usu- 

 ally distinctly apj)arent in the dead shells. 



The echiuated Cilobigerine forms are generally foimd in the 

 free state, being often taken in the towing-net with the Tha- 

 lassicoUidie or amongst the ingesta of Salpce and other pelagic 

 animals. After the death of the sarcocie, these little shells 

 gravitate to the bottom of the ocean, in company with the 

 siliceous frustules of Diatomaceiv and the crystal domes, con- 

 centric sj»heres, and the diverse spieular and fenestrated frame- 

 work of the Polycystina, Avhicli also enjoy a pelagic life. 

 Thus organic and sedimentary particles commingle to compose 

 incipient rocks, whose intimate structure at some remote 

 period may be studied with interest by future geologists. 



In Acanthomeira the animal sarcode is deposited centrally, 

 but at the same time superficially, around the conjoined bases 

 of the radiating spines, through the tubular axis of which 

 pseudopodial extensions of the sarcode may protnide. There 

 are, however, some pedunculated forms (such as are often to 

 be found attached to the keel of Atlanta^ the shells of Ptero- 

 poda, and other pelagic bodies) with exceedingly delicate and 

 imperforate spines radiating through a reddish-brown sarcode 

 mass surmounting the pedicle {^icanf/iometra, young'?). 



Professor Muller describes the sarcode of the Eucyrtidium 

 of Messina as an olive-brown fonr-lobed body occupying the 

 dome or summit of the shell, through the fenestrations of 

 which emerge fine pseudopodia like those of Actinoplinjs. 



3Iany of the free Polycystina{'?) taken in the towing-net ex- 

 liibit a remarkable alliance with the Thalassicollida?. Thus 

 a sarcode body, in every particular resembling a single pimc- 

 tum of the Thalassicolla imnctata of Huxley, or in some in- 

 stances two or three such bodies, were included within a more 

 or less open siliceous framework. 



The genus Diciyocha is an example of this group, which I 

 have little doubt should be referred to the Thalassicollidae. It 

 is certain, however, that they are at present confounded with 

 the Polycystina in the well-known fossil gatherings from 

 Oran, Barbadoes, and other places. 



Of course, where concentric shells are formed at intervals, 

 the mode of growth of the sarcode must be in all essential 



