INFUSORIA. 47 
described them as Molluscs. From the end of the last cell of the 
shell by one or more openings, or from numerous pores on the sur- 
face of the shell, thin contractile threads are extended which serve 
for motion. [On dissolving the calcareous matter from the shell of 
living species, there always remains an organic base of the exact 
form of the shell with all its pores and passages. This is a secre- 
tion effected by the contained animal mass. ScHuLTze’.| Enren- 
BERG thinks that these animals are allied to the Bryozoa (the so- 
called Polyps of Flustra, &c.); his principal reasons against their 
arrangement in the class of the Infusories are, that they have no 
polygastric intestinal canal, and that there is no other instance of 
calcareous shells amongst Infusories. 
On this division compare, amongst other works ; D’OrBieny, Tableau 
methodique de la Classe des Cephalopodes, Ann. des Sc. nat. premiere Série. 
Tom. VII. 1826. p. 245—315. Pl. ro—17. 
DusaRDIN, Observations nouvelles sur les Céphalopodes microscopiques. 
Ann. des Sci. nat., seconde Série. Tom. IIT. 1835. Zoologie, p. 108, 109 ; and 
Recherches sur les Organismes inférieurs. 1. Sur la Gromia oviformis et sur 
les Rhizopodes en général. ibid. Tom. IV. Zoologie, p. 343—352. Pl. 9. 
EnRENBERG, Ueber die Bildung der Kreidefelsen u. des Kreidemergels durch 
unsichtbare Organismen. Abhandl. der kiniglich. Akademie der Wissensch. 
zu Berlin. Aus dem Jahre 1838. s. 59—147. Also, Ueber noch sehr 
zahlreich lebende Thierarten der Kreidebildung und den Organismus der 
Polythalamien, &e. Aus dem Jahre 1839. s. 81—174, especially s. 1o6—r1o. 
A. D’OrpIGny, Article Foraminiféeres, Dictionnaire universel d’ Hist. nat. 
par Cu. D’ORBIGNY, Tom. V. 1845, p. 662—671. 
CraRK, On recent Foraminifera, Ann. of Nat. Hist. Sec. Series, 1850, 
Vol. V. p. 161—171. 
CaRPENTER, Microscopic Structure of Nummulina, &e, Journal of the 
Geol. Soc. of London, 1850. 
WILLIAMSON, On the minute structure of caleareous shells, &c. Trans. 
Microsc. Society of London, Vol. III. 1851, and euaeely Journ. of 
Microsc. Science, 1853, No. IV. p. 87. 
EHRENBERG, Das wirken des unsichtbaren kleinen Lebens auf der Erde, 
1854, Tab. XIX—xxx1I. Leipsig, 1854. 
Max. Siemunp Scuuurze, Ueber den Organismus der Polythal. &c. 
mit 7 uluminirten Tafeln, fol. Leipzig, 1854. 
On Noctiluca miliaris, which appears to belong to this division, though 
it does not emit expansions externally but has a moveable appendage 
attached, see QUATREFAGES Ann. des sc. nat. sec. Série Zool. xtv, p. 226-- 
235 Pl. 5, Kroun in Archiv f. Naturgesch. 1852 s. 77—81, Taf. 3, fig. 2. 
It is a chief cause of the phosphorescence in sea-water. 
To this family belong also some fresh-water species. 
1 SCHULTZE, op. cu. p. 7 
