a new Genus of Forammifera. 337 



" Such being the structure of the calcareous shell, it may 

 easily be seen that the chambers, besides being of uniform 

 shape, are so arranged that their axes are in a right line, each 

 chamber being altogether closed and fixed at both extremities 

 of its longer axis. It is therefore evident that this Foraminifer 

 belongs to D'Orbigny's order SticJiostegues. Further, it be- 

 comes the type of a well-defined genus, approaching in its 

 structure the Olandulince and Nodosartce^ but showing the 

 successive chambers completely enveloping each other, whilst 

 in the Olandulince they appear in part projecting to the ex- 

 terior, and in Nodosaria they are placed one on the top of the 

 other, overlapping each other but little, if at all. This will 

 show clearly how well-defined is the new genus, which I name 

 EUi])soidinay and that it is related to Nodosaria through Glan- 

 dulina. 



" By minute study of these microscopic shells, I succeeded 

 in distinguishing three specific forms belonging to the genus in 

 question ; and after I have recapitulated the generic characters, 

 I shall describe the species. 



" I was led to adopt the name ElUpsoidina in order to pre- 

 serve the generic terminology of the class, inasmuch as almost 

 all authors who have written on the subject, and especially 

 D'Orbigny, have derived the chief portion of their generic 

 terms from resemblances in external form : hence the name 

 given, referring to the nearly elliptical contom- of the shell, is 

 consistent with common usage. 



Characters of the Genus. 

 Ellipsoidina, mihi. 



" Shell free, regular, ovato-ellipsoidal, vitreous in texture, 

 terminated at one extremity by a tube, which is closed at the 

 base where it joins the shell. In the interior are a series of 

 chambers similar to the external one, decreasing in size, which 

 successively completely envelop each other, each attaching 

 itself to the base of that which immediately encloses it, and 

 fixing itself to the apex of the same by means of the extremity 

 of the tube. 



" Relations and Differences. — This genus, as I have already 

 remarked, is closely allied to Glandidina^ but it has sufficiently 

 distinct characters. The most remarkable fact is that, although 

 Ellipsoidina is multilocular, and hence very distinct from the 

 order Monostegia, still it is impossible, from exterior appear- 

 ance, to distinguish it from Oolina., so much do they resemble 

 each other externally ; indeed the form of the shell, the absence 

 of pores, the elongation of the anterior portion into a tube, the 



