188 DR. CARPENTER'S RESEARCHES ON THE FORAMINIFERA. 



imagined them to be opercula of Ammonites*; of Porpitce nummulares by STOB^US-|~ 

 and BROMELL|, who seem to have regarded them as representing the disks of the 

 existing Porpitae; of Helicites and Operculites by GUETTARD , who considered them 

 as opercula of Gasteropods ; of Discolithes by FORTIS ||, who supposed them to be 

 skeletons of mollusks ; of Madreporites by DELUC, and of Milleporites by FAUJAS 

 DE ST. FOND, whose idea of their nature is sufficiently indicated by the names they 

 assigned to them. 



2. The genus Orbitolites seems first to have been erected, and distinctly separated 

 from Nummulite, by LAMARCK, in the first edition of his 'Animaux sans Vertebres,' 

 its type being the O. complanata of the Paris basin. The following is his definition 

 of the genus, which he ranks between Lunulites and Millepora, among his "Polypiers 

 ForamineV': "Polypiarium lapideum, liberum, orbiculare, planum seu concavum, 

 utrinque vel margine porosum, nummulitem referens. Pori minimi, adamussim dis- 

 positi, conferti, interdum vix conspicui." These bodies, he says, are distinguished 

 from Nummulites by the opening of their marginal pores, and by the absence of 

 spiral arrangement in their minute chambers or cells. In his second edition (1816), 

 he altered the name from Orbitolites to Orbulites ; but the latter designation having 

 been previously employed in Malacology, the first appellation has been restored by 

 M. MILNE -EDWARDS in his posthumous edition of LAMARCK'S work. Under one of 

 the designations, Orbitolites or Orbulites, the genus has been recognized by SCHWEIG- 

 GER^[, BRONGNIART and CUVIER**, LAMOUROux-f-f-, DESLONGCHAMPS^|, DEFRANCE^, 

 BLAINVILLE ||||, BRONN^^, GOLUFUSS ***, MICHELIN "f~f~f", PICTET^^, and DUJAR- 

 DIN; none of whom, however, have either given any account of its internal struc- 

 ture, or made any essential modification in the definition of the genus, which they all 

 left in the place which LAMARCK had assigned to it. 



3. The existence of more than one recent species of the same type was indicated 

 or expressly mentioned by several of the foregoing writers. Thus FORTIS tells us 



* De Conchis minus notis, 1739 (fide D'ARCHIAC et HAIME), and App. Phytol. F. Coll. 1764 (fide RUPERT 

 JONES). 



t Dissertatio epist. ad W. GROTHAUS de nummulo Brattenburgensi, 1732; Opera petrefactorum, 1752; 

 Opusculis, p. 6 (fide D'ARCHIAC et HAIME). 



J De Nummulo Brattenburgico, in Act. Litt. Suec., vol. ii. p. 50 (fide D'ARCHIAC et HAIME). 



Memoires sur differentes parties des Sciences et des Arts, 1770. 



|| Memoires pour servir a 1'Hist. Nat. de 1'Italie, 1816, vol. ii. ; and Journal de Physique, 1801, vol. lii. p. 106. 



f Beobacht. auf Naturg. (1819), pi. 6. 



** Ossemens Fossiles (1822), vol. ii. pt. 2. p. 270. 



ft Expos. Method, des gen. des Polypiers (1821), p. 44. pi. 73. 



U Encyclop. Method., Zooph. (1824), p. 584. 



Dictionn. des Sci. Nat. (1825), vol. xxxvi. pp. 294, 295. 



HII Manuel d'Actinologie (1830), p. 411. pi. 72. f f Lethsea Geognostica (1836-37), pi. 35. 



*** Petrefacten (1826-33), vol. i. p. 41. pi. 12. ftt Icon. Zoophyt. (1845), p. 167. pi. 46. 



JU Trait^ Element, de Paleontologie (1844-45), torn. iv. 



Diet. Univ. d'Hist. Nat., tome ix. (1847), p. 162. 



