GENUS PENEKOPLIS: HISTOET AND DISTRIBUTION. 3 



fication of those pores. For he goes on to state, " Cette coquille est encore pellucide, et 

 permet de lire au travers de son tet la serie et la disposition des nombreuses cellules de 

 chaque concameration ; ces cellules deviennent plus grandes a mesure que la coquille prend 

 plus d'accroissement. II est probable que leur nombre repond a celui des animaux qui les 

 habitent, et qui les constituent simultanement pour former un nouveau rang." This sub- 

 division of the principal chambers into cells, each occupied by a separate animal, exists 

 only in the imagination of MONTFORT, who seems to have been misled by the peculiar 

 markings of the surface of the shell, which, as will be presently seen, are merely superficial. 

 LAMARCK, not adopting MONTFORT'S genus, referred the Nautilus planatus of FICHTEL and 

 MOLL to the genus Cristellaria, with which it has no relationship whatever ; and having 

 copied their figures into the ' Encyclopedic Methodique *,' he designated one set of forms 

 as C. planata, and another as C. dilatata, subsequently reuniting them, however, under 

 a new specific name, C. sguammula^. The genus Peneroplis has been recognized by 

 BLAINTILLE J and by EHRENBERG ; and D'ORBIGNY has applied this name, in his various 

 writings on Foraminifera, to the form described by FICHTEL and MOLL, whilst he has 

 created a new generic term, Dendritina, for a' series of closely allied forms, in which 

 there is a single large dendritic aperture instead of a linear series of separate apertures. 

 The distinctive characters of these two genera, as last given by him||, are as follows: 

 " Peneroplis ; coquille nautiloide comprimee, pourvue de nombreuses ouvertures sur 

 une seule ligne a la demiere loge seulement. Cavite simple : Dendritina ; ce sont des 

 Peneroplis dont les ouvertures anastomosees ferment une dendrite." In addition to 

 these, I shall cite his definition of another genus, established by LAMARCK in 1801, 

 which, as I shall presently show, consists, like Dendritina, of mere varieties of Pene- 

 roplis: " Spirolina ; coquille nautiloide dans le jeune age, projetee en crosse dans 1'age 

 adulte." 



122. The genus Peneroplis is very widely diffused through warmer latitudes; indeed 

 few collections of Foraminifera from sands or dredgings taken from the Mediterranean, 

 the ^Egean Archipelago, the Red Sea, the East or West Indies, the Philippine seas, or 

 the shores of Australia or the Polynesian Islands, will fail to present numerous examples 

 of it. A few specimens have been found on British coasts ; but it is surmised by Pro- 

 fessor WILLIAMSON that these have been brought by the Gulf-stream from the West 

 Indian Seas. " Amongst the multitude of West Indian seeds and other light objects 

 thus thrown upon our north-western shores, it was to be expected that some of the 

 tropical Foraminifera would be entangled ; and such may have been the case with the 

 species under consideration^." The finest examples I have met with were contained in 



* Tab. 467, figs. 1, a, b, c, 2 ; a, b, c. f Animaux sans Vertebres, torn. vii. p. 607. 



J Malacologie, p. 372. 



" Tabellarische Charakteristik der Bryozoen-Classe und sammtlicher Familien und Gattungen der 

 Polythalamien," in Berlin Transactions, 1838. 



|| Cours lilementaire de Paleontologie, 1849, torn. ii. p. 198. 



If On the Eecent Foraminifera of Great Britain, published by the Bay Society, 1858, p. 46. 



u2 



