REPORT ON THE FORAMINIFERA. 
463 
The subordinate modifications are for the most part distinguished by the different degrees 
of development of features already present in the type, and in but few is there any new 
feature superadded. 
It frequently happens that, in restricted areas, the striate or costate Lagena are 
divisible into tolerably well-marked groups, which it is impossible to preserve when gather- 
ings from wider limits or more extended bathymetrical range are taken into account. 
This fact has already been adverted to in the case of Lagena striata. I am assured 
by my friend Mr. Joseph Wright of Belfast, who has given much attention to the subject, 
that in the Irish (and therefore presumably in the British) seas, there are two modifications 
of Lagena sulcata , namely, Lagena williamsoni and Lagena costata, which are always 
distinguishable from the typical form ; the former by a ring of reticulated or hexagonal 
ornament at the base of the neck, the latter by the really sulcate rather than costate 
condition of the surface. Of these, Lagena williamsoni at any rate is probably a good local 
variety, the characters partaking more or less of those of Lagena hexagona ; but there is 
much less to go upon in the case of Lagena costata, which, viewed from a wider stand- 
point, appears only as one of innumerable individual modifications of the parent form. 
Lagena sulcata is one of the most abundant and most generally diffused of all the 
members of the genus. It is at home in every latitude from Baffin’s Bay and Smith Sound 
or the shores of Novaya Zemlya, to the equator ; and from the equator to Heard Island, far 
south in the Southern Ocean ; and the bathymetrical range extends from the littoral zone 
to a depth of 2750 fathoms. 
Its geological history is similarly extensive. It has been discovered by Mr. John 
Smith of Kilwinning, in shales of Upper Silurian age, at Lincoln Hill, Woolhope, and a 
very similar though perhaps varietally distinct form occurs in the Carboniferous Lime- 
stones of the north of England and of Scotland. It is present in the Lower Lias of 
Yorkshire (Blake), and recurs in almost every subsequent microzoic deposit down to recent 
times. 
Lagena sulcata, var. interrupta, Williamson (PL LVII. figs. 25, 27 ; apiculate 
specimens, PI. LVIII. figs. 5, 6). 
Lagena striata, var. interrupta, Williamson, 1848, Ann. and Mag. Nat. Hist., ser. 2, vol. i. 
p. 14, pi. i. fig. 7. 
,, vulgaris, var. interrupta, Id. 1858, Rec. For. Gt. Br., p. 7, pi. i. fig. 11. 
,, alternans, Terquem, 1875, Anim. sur la Plage de Dunkerque, p. 21, pi. i. fig. 4. 
,, interrupta, Id. 1882, Mem. Soc. geol. France, ser. 3, vol. ii., Mem. III. p. 27, 
pi. i. fig. 10. 
As stated by Williamson, this variety only differs from the typical Ljagenct sulcata, 
“ in the unequal lengths and discontinuous character of the costse, which sometimes do 
not extend over more than one half of the shell.” 
The distribution is practically identical with that of the type. 
