NOTES ON RETICULARIAN RHIZOPODA. 59 



simple, situate on the face of the terminal segment near its 

 junction with the previous convolution. Colour buff to 

 reddish brown ; surface smooth, not polished. Diameter -jJl. 

 inch (2*5 mm.). 



This handsome species differs from its congeners in size as 

 well as in general contour. The larger specimens are fully 

 one tenth of an inch in diameter, and are coronate or bicon- 

 cave in form. The chambers are few in number, tent-like, 

 and more or less embracing, though the successive convolu- 

 tions do not entirely conceal those immediately preceding 

 them. The width of the spiral band increases with each 

 turn, and the chambers of the final whorl are very much 

 larger than those of the earlier ones. The texture of the 

 test is uniformly very finely arenaceous and opaque, but 

 within certain limits, i.e. from a creamy white to a dark 

 brown, the colour varies a good deal. Amongst previously 

 described Foraminifera it is not easy to find any with cha- 

 racters approaching those of Trochammina coronata ; per- 

 haps the nearest is Tr. injlata,h\xt in that species the test is 

 Rotaliform, in other words, all the segments are more or less 

 exposed in a spiral line on the superior face, whilst those of 

 the last convolution only are visible on the inferior side, 

 which is very different from the symmetrical, nautiloid habit 

 of the new species. 



Fine specimens of Tr. coronata have been met with at the 

 western side of both the North and South Atlantic, namely, 

 at two stations near the West Indies (390 fathoms and 450 

 fathoms), and at two stations off the coast of South of America 

 (675 fathoms and 1900 fathoms). 



Trochammina lituiformis, n. sp. PL V, fig. 16. 

 Characters. — Test free, crozier- shaped; consisting of an 

 irregularly septate or pseudo-septate tube, spiral at its com- 

 mencement, afterwards linear. Segments irregular in size, 

 subcylindrical or ventricose ; sutural lines excavated. 

 Aperture simple, terminal. Surface smooth ; colour light 

 brown. Length y inch (3'7 millim.). 



There are already known at least two crozier-shaped 

 varieties of Trochammina, the Carboniferous Tr. centrifuga, 

 and the Permian Tr.Jlhim, hut these are alike characterised 

 by the absence of septa both in the spiral and linear portions 

 of the tests, and pertain rather to the Ammodiscus series than 

 to Trochammina proper. They are also, both of them, com- 

 paratively minute in size. The specimens now described are 

 of fine dimensions, though somewhat irregular in genera 



