NOTES ON RETICULARIAN RHIZOPODA. 281 



uniformly from one end, instead of alternately from the two 

 extremities. 



The test of Chilostomella may be described in general 

 terms as composed of a series of nearly symmetrical, ovate, or 

 elliptical segments, each enclosing the whole of that 

 previously formed, with the exception of a small portion of 

 its end. The order of the segments is alternate, that is to 

 say, they are put on first from one end, then from the other. 

 The line of union is not directly transverse but dips towards 

 one side, so that more of the penultimate chamber is exposed 

 at one side than at the other. The aperture is crescentic, 

 sometimes bordered by a thickened lip, and always situated 

 on the margin of the final segment in the region nearest to 

 the apex of the shell. In shape the test varies from an 

 elongate, sub-cylindrical, to a short, rounded, oval, between 

 which extremes every variety of contour may be met with ; 

 the ends are sometimes blunt and rounded, sometimes more 

 or less tapering, so that, unless Professor Reuss's two 

 species {Ch. ovoidea and Ch. Czjzeld) have some better dis- 

 tinguishing feature than mere size and external form, they 

 may very safely be resolved into one. In deep water the 

 specimens are often more delicate and transparent, and also 

 more elongate than in shallow seas, but this is by no means 

 an invariable rule. One or two individuals of this species 

 have been found amongst the gatherings of surface Forami- 

 nifera, but there seems no reason to suppose that the type is 

 essentially a pelagic one. 



Cldlostomella ovoidea has been met with at " Challenger " 

 stations in the North Pacific, South Pacific, and North 

 Atlantic. It also occurs in one. or two of the "Porcupine" 

 dredgings from more northerly areas in the Atlantic than 

 any point of the "Challenger" voyage, and the Rev. A. 

 M. Norman has obtained the species in some abundance 

 on the coast of Norway. The recorded depths of the 

 " Challenger " dredgings in which it has been found are 

 nearly all between 300 and 600 fathoms, but one of them is 

 as deep as 2300, and another as shallow as 95 fathoms. 



(?eww5— ALLOMORPHINA, Reuss, 



Allomorphina trigona, Reuss. PI. VIII, figs. 13, 14. 



Allomorphina trigona, Reuss, 1849. 'Deuksclir. d. math,-uat. CI. k. Akad. 

 d. Wiss./ vol. i, p. 380, pi. 48, fig. 14. 

 — cretacea, Reuss, 1850. 'Haidinger's Abhaudl.,' vol. iv, p. 42, 



pi. 5, fig. 6. 



The genus Allomorphina differs from Chilostomella hi 



