50 



INVEKTEBRATE ANIMALS. 



the sarcode is exposed, whether this be only at the mouth of the 

 shell, as in Miliida (tig 9, h), or whether it be over the whole 

 surface, as in DUmrhina (lig. 9, c), it has the power of giving off 

 pseudopodia. The pseudopudia, however, differ greatly from those 

 of the Aiiiirhii, aud they show some remarkable characters. They 

 are extremely long thread-like processes, instead of being blunt and 

 finger-shaped (fig. 8, h), and they have the curious property that they 

 run into one another and interlace towards their extremities, so as 

 to form a network which has been aptly compared to an "animated 

 spider's web." Lastly, the microscope reveals in the pseudopodia 



Fig. 9. — Morpholcgy nf ForaiiiinilVra. a Lagemt. vulgaris, a jiKUintlialauinLis Foraiii- 

 inifer ; h Milioki (after Schultzf), shnwintr tlie pseiidnp.nlia ]n-<itnn]r(i from the oral 

 aperture of tlie shell ; c Di.^corhlii.'i (after Seliiiltze), .slinwiiif,^ tlie iiaut iloid yliell v. ith 

 foraiuhia in llie sliilUwalls, ^n\iii;; exit In ]iseu(lnji(.ilia ; '! Weetioil of Xodosaria 

 (after Carl«-iiler) ; e Xoilnxinni. Iiiyi,]u; f i:lnl,igcri ua bii/hnda,. 



a very curiovis circulation of minute solid ])articles or granules, which 

 travel in all directi(jns through the pseudopodial jietwoi-k. Tnter- 

 nally, the sarcode-body of the Funi/iiiiiifi'ni is of a verv simjile 

 structure ; but a nucleus and contractile vesicle are usually, if not 

 invariably, ]iresent. 



Simjile as is the sai'code-body of the Forciminifcra^ it has in all 

 cases the jiower of secreting a skeleton or shell, which is technically 

 called tlie " test " (Lat. testa, a shell). The shell is usually " ca.lcare- 

 i>iis " — that is to say, composed of carbonate of lime ; but it is sonie- 

 tinu's " areuacKous," or composed of particles of sand united tiigethcr 



