426 Mr. H. J. Carter on Orbitolites Malabarica. 



by the addition of more rows of chambers on the one hand, and 

 more septa on the other, just as in Orbitoides. D'Orbigny's 

 " coupe horizontale," therefore, of the latter (Cours element, de 

 Paleont. et Geol. vol. ii. p. 193) is not correct, for that is iden- 

 tical with the lines on the back of an engine- turned watch. 



Locality. — Abounding in an impure, bluish-green limestone 

 (of the Pleiocene of formations) about 30 feet beneath the surface 

 at Cochin on the Malabar coast, the shells of which, though 

 deprived of their animal matter, are still white and pulverulent, 

 or semicrystalline. 



Observations. — In my "Descriptions of some of the larger 

 forms of Foraminifera in Scinde," p. 161 of this Journal, I have 

 stated, that " D'Orbigny is not warranted in giving the distin- 

 guishing character of concentricity to the rows of chambers in 

 his order Cyclostegues, for in his three first genera, which are all 

 alike in this respect, we have seen that it is almost impossible to 

 determine it ; and in his last one, of which Lycophris dispansus 

 is a type, it is evident that this is not the case, but, that the 

 chambers are arranged subspirally." 



I had always been impressed with the idea that a spiral 

 arrangement of the chambers was the most persisting character 

 in the discoidal Foraminifera, and although I had succeeded in 

 demonstrating this in Orbitoides {loc. cit.), I could not do so in 

 the other genera of D'Orbigny's Cyclostegues, from the small- 

 ness of the cells and their confusion in the centre of the species 

 I possessed. In the one just described however, there is no 

 doubt of it. The lines of chambers are thrown ofi^ from a vertical 

 spire, in the form of sparks from a rotatory fire-work, as I have 

 before stated of Orbitoides; and, if it be the case in one species 

 of Orbitolites, it is most probably the case in all, and in D'Or- 

 bigny's genus Orbitolina also, which is but an extended form of 

 the same structural foundation. 



Hence if this reasoning be allowed, it must follow, that 

 D'Orbigny's term for this order is a misnomer, for the chambers 

 are not arranged in concentric circles as it would imply, but 

 spirally, as in other discoidal Foraminifera. 



I have named this species Orbitolites Malabarica from its 

 locality, the specific differences between it and the other known 

 species (with the exception of the spiral lines on the surface) not 

 being recognizable by the unassisted eye. 



Identity of Lamarck's genus Orbitolites and D'Orbigny's 

 Cyclolina. — There appears to me to be very little difference 

 between Lamarck's genus Orbitolites and D'Orbigny's Cyclolina, 

 judging from the figures of the former, in tab. 73. figs. 13-16, 

 of Lamouroux's 'Exposition Methodique des Polypiers,' and of 

 the latter, in tab. xxi. figs. 22-25, of D'Orbigny's ' Foramen. 



