﻿MR. F. W. O. RYMER JONES ON SOME JAVAN DEEP-SEA LAGEN.E. 51 



Prof. Williamsoii depicts a form of L. (Entosolenia) squamosa, var. hemgom, wliich has 

 the appearance of two similar forms joined at their bases ; while Messrs. Parker and 

 Rupert Jones delineate three fossil structures of L, Icevis (pi. xviii. figs. 10, 11, & 12), 

 from the Grignon beds (Eocene), which take on a second lateral chamber. A rather 

 interesting " wild " growth from the Java seas is depicted in fig. 5, in which the flask- 

 shaped form not only takes on a second upper chamber, but the walls of this cell become 

 double, and enclose a third, while a fourth chamber extends up the whole length of the 

 exterior of the opposite side. 



Lagena vulgaris, Williamson, var. fisstirina, Reuss. (Pigs. 6-8.) 



The chief distinguishing characteristic of this group is the compression of the orifice 

 into a wide " ornithorhynchoid " beak ; and Prof. Reuss has therefore raised it to the 

 rank of a special genus, under the name Fissurina. It, however, so narrowly resembles 

 Lagena in all save the compression of the aperture, that it has been considered by 

 Messrs. Parker and Rupert Jones to be insufiiciently differentiated to be separated from 

 them, from the fact that among the compressed forms of Lagena^ many of which are 

 included by Prof. Reuss in this genus, the orifice would naturally have a tendency to 

 become flattened in proportion to the amount of compression of the lateral walls, espe- 

 cially where there is no internal tube to counteract this ; and therefore the chief charac- 

 teristic of Fissurina loses its generic value, especially as in fig. 8 is delineated a form from 

 the Java seas in which the shell possesses a decided external neck— an occurrence 

 which more effectually breaks down the partition-wall between Lagena and Fissurina. 

 Still the compression of the septal aperture undoubtedly does occur even among forms 

 provided with an internal tube (figs. 7, 8) ; and therefore I have for the present retained 

 the name as that of a varietal form. Pig. 6 somewhat resembles the JP. apiculata of 

 Reuss (Monogr. taf. vi. fig. 85), but is more produced, while fig. 7 is an elegant entoso- 

 lenian variety of the more elongated and tubeless F, ohlonga^ Reuss. 



Lagena vulgaris, "Williamson, var. gotUca, Nov. (Fig. 9.) 



Shell ovate, tapering towards the anterior, gently rounded at the base. Walls thin, 

 hyaline, smooth, and finely foraminated. Internal tube very short and stumpy. 



The external decoration is very remarkable, consisting of several delicate, narrow, 

 longitudinal bands of mUky whiteness, passing three fourths up the shell, where they 

 curve over and form elegantly pointed arches. These are about six in number, and are 

 very sUghtly, if at all, raised from the surface. The shell appears slightly broken at the 

 orifice, and is at present the only one of the kind I have met with. 



Lagena vulgaris typica, Williamson. (Pigs. 10-13.) 



These forms resemble L, glohosa in aU its many modifications of contour, the chief 

 difPerence being in the possession of an external neck. The base of the shell ako varies 

 in outline, sometimes being more or less apiculat^ (figs. 10, 11 ; and L. clavata, WilUam- 



MISSOURI 

 BOTANICAi- 



GARDEN. 





