346 
ME. W. K. PAEKEE AND PEOEESSOE T. E. JONES ON SOME 
graph of British Recent Foraminifera,’ 1857 ; to Dr. Carpenter’s ‘Introduction to the 
Study of Foraminifera,’ 1862 ; and to Professor Reuss’s ‘ Monographic der Lagenideen,’ 
Sitzungsber. Akad. Wiss. Wien, vol. xlvi. 1 Abth. 1863 (read June 1862); and for the 
strict determination of the species noticed by Walker, Jacob, and Montagu, and for 
some special remarks on Lagence , we refer to our own Papers .in the Annals Nat. Hist. 
1857, &c. 
On account of their extreme variability (within certain limits) as to shape and orna- 
ment, without any definite break in the range of the modifications being recognizable, 
it is impossible to fix on any distinctive character, or set of characters, sufficiently 
limited in development to be of real importance in dividing the Lagence into even two 
species. For convenience, however, we must take the best marked shapes and ornaments 
as indicating subordinate or varietal types, around which the diverging modifications 
may be grouped in an artificial classification. 
This has been nearly completely accomplished, in his “ Monographie ” above referred 
to, by Professor Reuss; who, however, regards these subordinate divisions as “ species.” 
The addition of some striking varieties chiefly found in the warm seas, including the 
two-mouthed elongate forms, and the correction of some errors in the synonymy, arising 
mainly from mistakes as to Walker’s and Montagu’s Lagence , would still further 
improve Professor Reuss’s classified and illustrated conspectus, of the chief members of 
this group of elegant little single-chambered Foraminifera; and, without doubt, his 
so-called “genus” Fissurina is open to criticism, as we shall see further on. 
Lagena , including both those that have external apertural tubes (Ectosolenian) and 
those with internal neck-tubes (Entosolenian), have their chief features of shape and 
ornament shown by globose, ovate, and fusiform shells, either smooth, partly or wholly 
ribbed, reticulate, or granulate and spinose ; also by more or less compressed shells, of 
round or oval outline, with and without linear and reticulate sculpture ; further, the 
base of the shell, opposite to the aperture, becomes apiculate, produced, and perforate, 
in any of the above-mentioned kinds of shell, resulting in a more or less fusiform and 
perforate, or clistomatous, condition. 
Taking the smooth forms, varying from egg-shaped to flask- and amphora-shaped, with 
or without long necks, we have the “ lsevigatee” of Reuss, among which L. globosa, 
Walker and Jacob, L. Icevis, Montagu, and L. clavata , D’Orbigny, represent the three 
best-marked stages. Reuss includes also the apiculate smooth forms in this group ; but 
we prefer to bring them into relation with the perforate forms, to which we believe they 
strongly tend. 
Those with furrows, riblets, and ribs are the “ striate aut costate ” of Reuss. They 
are led by L. semistriata , Williamson, from out of the smooth forms up to L. sulcata , 
Walker and Jacob, and even more coarsely ribbed shells, with modifications of form 
exactly corresponding to those of the smooth varieties ; but no particular stage of shape 
and of ornament can be said to be permanently associated. 
In the “reticulate” (Reuss) the longitudinal riblets become united by cross-bars, of 
