﻿MR. F. W. O. RYMER JONES ON SOME JAVAN DEEP-SEA LAGEN^. 63 



the same as the fossil form depicted by that author (Monogr. taf. y. fig. CO) from the 



Septanan clay of Pietzpuhl, near Potsdam, and which Prof. Reuss raised to the rank 

 of a special genus under the name of X. oxy.tomu. These characteristics, however, are 

 too variable to be of importance. 



Lagena vulgaris, var. squamosa, Williamson. (Fig. 51.) 



Shell subglobular or ovate, slightly compressed, somewhat prolonged anteriorly, at the 

 centre of which is situated the aperture. Walls semiopaque and of a dirty white hue. 

 Internal tube short. The external surface is ornamented witli numerous brge ai-eola3, 

 arranged in longitudinal rows, each series of areolar spaces being so disposed'' thai fhe 

 transverse walls of each alternate with those on either side of it. 



^ In the form here depicted these depressions arc very large and four-sided, their lateral 

 diameter being generally greatest. These quadrilateral spaces, however, have a ten- 

 dency to become hexagonal, the shell being evidently a marginate variety of JSJ. squamosa, 



scalariformis, of Prof. Williamson- (Monogr. p. 13, pi. i. fig. 30), thon-h the 1 



gitudinal ridges in the form here delineated (fig. 51) arc almost straight instead of 



being zigzag, and are, together with the transverse ribs, very well developed and 



trenchant. The periphery of the shell is encompassed by a well -developed marginal 

 keel. 



Dr. Macgillivray has noticed this compressed character in his Lagcnula reticvhita 



(• Molluscous Animals of Aberdeen,' p. 28), wliich Prof. Williamson, however, considered 



to be merely adventitious ; but the shell here depicted, the only reticulate form I have 



met with in this sounding, has this peculiarity very apparent ; and I am therefore inclined 



to regard it as a normal variety of the Reticulate series, with which it forms an inter- 

 mediate link. 



Lagena vulgaris, Williamson, var. ampiilla-distoma, Nov. (Fig. 52.) 



* 



This shell closely resembles some of the varieties of L. glohosa, having the 8haj)e of a 

 distended globe, the walls, however, being roughened by exogenous shell-deposit. From 

 the anterior of the shell there projects an internal straight tube, passing three fourths 

 down the cavity, and terminating in a trumpet-shaped orifice; at the centre of the ba'^'', 

 however, there projects a short external tube in the same axial line as the internal one. 

 Owing to its roughened exterior, it cannot be classed among tlic smooth forms of 

 X. disioma-polita of Messrs. Parker and Eupert Jones; and therefore it must, for flu; 

 present at any rate, be considered a separate variety, for which I propose the de'^icrnation 

 X. ampulla-distonia. 



These distomatous organisms are connected with the smooth cntosolcnifln varietlcji 

 through the apiculatc forms, to which they arc closely allied, the base of the shell hdx\^ 

 more or less drawn out and perforated (see, for eioimple, fig. 53). Mch-rs. Parker and 

 Rupert Jones have united these with the apiculate varieties under the names L, apicu- 

 ^ta, Eeuss, and cauduta, D'Orbigny (Monogr. p. 358) ; but as I have already adoptiHl 

 D'Orbigny's name caudata for the striated form depicted in fig. 22, which also in 

 this respect resembles his OoUna caudata, I have united the organism depicted in fig. 63 



