﻿t 



MR. F. W. 0. RYMER JONES ON SOME JAVAN DEEP-SEA LAGEN.E. 61 



■ 



The shell is further decorated by four longitudinal rows of blunt or rounded bosses, a 

 few mmute granules being also sparsely scattered over the otherwise smooth sur^ice. 



Lagena vulgahis, Williamson, var. pertuso-marginata, Nov. (Fi^-s. 46, 47.) 



_ » 



These elegant, symmetrical, flask-shaped structures are chiefly characterized by the 

 perforation of their shell- walls, the external surface being covered with deep " pittings," 

 in the hollow of each of which the pseudopodial orifices most probably open. In fig. 46, 

 which appears to be a young shell, the pittings are smaller and the walls transparent; 

 while in the more opaque form, delineated in fig. 47, the perforations are larger, and are 

 visible only partway up the neck, the upper half of which suddenly becomes imperforate 

 and glassy. The anterior of these shells tapers more or less gradually into a well-developed 

 external neck, the orifice of which, in fig. 46, is encircled by a patulous and lipped 

 border. The periphery of the flask is encompassed by a marginal keel, which in ^v^. 16 

 is very narrow and translucent, passing completely round i\w ba«?e and up tlie sides of 

 the neck; while in fig. 47 it presents a more plicated ajipearancc and is more opaque, in 

 addition to which it is absent at the extreme base, and also at the upper part of t lie 

 neck. The base of this form (fig. 47) is provided with an exceedingly short basal tube 

 of very narrow diameter, which projects into the shell. This would seem to indicate the 

 existence of an orifice at the basal end also ; and on subjecting it to a high magnification 

 such appears to be the case. The tube, which measures about t^\,o of an inch in lenirth 



3 0^0 of an inch, in diameter, communicates with the exterior of the shell by ;j 

 orifice of equally small dimensions, but which does not project externally beyond tl 

 shell- wall. A basal tube in all respects similar to the above is also present in fig. 12. 



Lagena vulgaris, Williamson, var. helophoro-marginataj Nov. (Fig. 48.) 



Shell subglobular, compressed ; walls thick, of a dirty white hue, widely curved at the 

 base and anterior end, and covered with blunt rounded bosses. Internal tube flexuous, 

 reaching almost to the bottom. Anteriorly this tube 2)asse8 out into a short neck, the 

 orifice of which is thickened by a " turned *' rim. Around the periphery of the shell 

 passes a narrow, trenchant, keel-like, transparent band, which extends along either side 

 of the external neck-tube, enveloping it, and giving it the appearance rather of a straight 

 tubular canal than of a nisck. At the base this projecting keel forms two transparent 

 and blunt horns, between which is a third and smaller one. 



In external ornamentation this form bears a close resemblance to the L. aJtpem and 

 X. rudis of Eeuss (Monogr. taf. vi. figs. 81, 82); but, unlike them, it is prnvided with 

 the marginal keel and external neck-tube. 



Lagena vulgaris, Williamson, var. siliqua, Nov. (Fig. 49.) 



Among the innumerable protean forms which arc found among these monothalamout 

 organisms, one occasionally meets with shells which depart «^ crrcatly from th^ true 

 Lagena character, that it becomes a matter of some difficulty to determine whether they 

 are true varietal forms or merely abnormal growths. 



The shell represented in fig. 49 is perhaps one of the most remarkable, diffcnng c(m- 



