282 HENRY B. BRADY. 



having three chambers to each circuit instead of the alter- 

 nating two, and, as its growth takes place on one plane, the 

 test assumes a sub-triangular and more or less depressed 

 contour. There does not appear to be any morphological 

 distinction between the two " species" above quoted, and 

 mere difference of geological age is of little value frotn a 

 zoological standpoint ; nor can the fossil specimens be 

 separated from the recent ones by any character of specific 

 or even varietal significance. In the living condition 

 AUomorpliina is exceedingly rare, and the individual 

 specimens are small and delicate. The genus is supposed 

 to have made its appearance earlier than its ally Chilostomella , 

 and it may in like manner be the first to die out. 



In two dredgings only has AUomorplima trigona been 

 found recent; one of these is from the Hyalonojia-^iround to 

 the south of Japan, in 345 fathoms, the other, off Tahiti, in 

 620 fathoms. 



Gewws— PAVONINA, d'OrUgny. 



Pavonina FLABELLiFORMis, cPOrligmj. PI. YIII, figs. 



29, 30. 



Pavonina JlabeUiformiSy d'Orbigny, 1826. 'Ann. Sci. Nat.,' vol. vii, p. 260, 

 No. 1, pi. 10, figs. 10, 11 :— Modele, No. 56. 



D'Orbigny obtained this rare and interesting Foraminifer 

 from Madagascar prior to 1826, and from that time until a 

 year or two ago, when I had the good fortune to meet with 

 it in some sand dredged by my friend Dr. E. Perceval 

 Wright, in shallow water in the Seychelle Islands,^ it had 

 not been found by any subsequent naturalist, and much 

 doubt had been expressed as to its structure and affinity. 

 Messrs. W. K. Parker and T. R. Jones suggested, in one of 

 their papers on the Nomenclature of the Foraminifera,- that 

 it might *' possibly be a symmetrical Peneropolis, more 

 probably a semi-discoidal modification of Orbitolites." But 

 the specimens now brought to light show that its place is 

 far from the porcellanous series, and that the morphological 

 difficulty has arisen from a slight inaccuracy in d'Orbigny's 

 figure and Model, which has probably arisen from defective 

 microscopic powers. Careful examination of the specimens 

 reveal the fact, not very clear at first sight, that the early 

 chambers are not spiral or subspiral, as they appear to be, 



1 'Ann. and Mag. Nat. Hist.,' 1877, ser. 4, vol. xix, p. 105. 



2 Ibid., 1S63, ser. 3, vol. xii, p. 440. 



