58 HENRY B. BRADY. 



Trochammina ringens is nearly allied to the species last 

 described ; the points of distinction, are nevertheless suffi- 

 ciently apparent. Compared with Tr. trullissata, it has only 

 about half the number of segments in each convolution, and 

 the final whorl completely encloses the previous ones, instead 

 of leaving the penultimate coil partly exposed at the centre. 

 The general contour of the test is biconvex rather than 

 depressed in the umbilical region, and the terminal segment 

 is conspicuously large. In colour, texture, and minute struc- 

 ture, the two forms are alike, but Tr. ringens has none of 

 the reticulation of the inner surface of the shell that has 

 been ascribed to Tr. trullissata. 



It appears to be a very rare species. I have only notes 

 of its occurrence in three of the '' Challenger " dredgings, one 

 of them from the North Atlantic, off Siera Leone (1750 

 fathoms), one from the South Atlantic, off Buenos Ayres 

 (1900 fathoms), and the other from the North Pacific (1850 

 fathoms). 



Since the above description was written I find that the 

 Rev. A. M.Norman has this form also in his collection from 

 the " Valorous" dredgings at the entrance of Davis' Strait, 

 in 1750 fathoms. 



Trochammina pauciloculata, n. sp. PI. V, figs. 13, 14. 



Characters. — Test ovoid, slightly compressed, obscurely 

 spiral ; composed of about two convolutions, the latter of 

 which almost entirely conceals the earlier one. Segments 

 few, usually three in each convolution, inflated; sutures 

 slightly constricted. Test thin, finely arenaceous, brown ; 

 exterior smooth, often polished ; interior smooth. Aperture 

 a curved slit on the superior surface, at the inner margin of 

 the last segment. Length, -^ inch (0*45 millim.). 



Though a very minute species Troehammina pauciloculata 

 is striking and distinct. It is isomorphous with the genus 

 Allomorphina of Reuss, the recent specimens of which are 

 of even smaller dimensions, but it has the shell texture 

 characteristic of its own genus, whilst Reuss's type is hyaline 

 and perforate. In its general plan of growth it closely 

 resembles the Rotalians, notwithstanding its small number 

 of segments, and their unsymmetrical disposition. 



Trochammina coronata, n. sp. PI. V, fig. 15. 



Characters. — Test nautiloid, biconcave, composed of few 

 convolutions ; peripheral margin lobulate and rounded. Seg- 

 ments distinct, variable in number, inflated. Aperture 



