﻿MR. F. W. O. RYMER JONES ON SOME JAVAN DEEP-SEA LAGEN^. 53 



I - ' If- , 



times subcylindrical and elongated, passing through every intermediate modification of 

 contonr, while the shell-walls are glassy and transparent, not unfrequently being some- 

 what opaque and finely foraminated. 



The exterior is ornamented with a variable number of thin trenchant riblets, which 

 pass longitudinally up the shell-wall, terminating sometimes at the base of the neck or 

 extending up its sides, and also occasionally project from the base, forming a more or 

 less wide coronal (fig. 20). Sometimes these striations are more or less interrupted 

 (fig. 18), some of them occupying the middle portion of the flask only. 



The greater number of these forms taper towards the anterior more or less gradually 

 into a well-formed external neck, though examples occasionally occur which are deficient 

 in this respect. Among these is one which somewhat resembles the X. Uaiduifjcn^ 

 Czizek (Reuss, Monogr. p. 326, taf. iii. fig. 41), the only apparent dilTprence being that 

 in the shell depicted by that author the neck is external, while in that from the Java sea 



the tube is introverted. 

 The L. amphora of Prof. Reuss, from the Septarian clay of Pietzpuhl (taf. iv. fig. 57), 



is a slightly bulged variety. In a somewhat slender form there is a snuill swellin 



o 



near the top of the neck, which resembles the cicatrix on the body of a wounded 

 earth-worm, the small portion Of neck-tube above this being slightly bent out of the 

 axial line — giving the appearance of having been broken, and repaired by the contained 



microzoon 



Around the base of the neck of the globose form depicted in fig. 18 are observable a 

 few feeble parallel rings of exogenous shell-deposit. 



In the entosolenian structures (figs. 19, 20) the walls contract towards the anterior 

 into a very stumpy lipped neck, while the base is rounded or sharply npiculatc. The 

 shell- walls are more glassy and the striae fewer in number than in the preceding figures, 

 being reduced to about six. These take their origin from the margin of the rim, and ps"*^ 

 longitudinally down the sides to the base in transparent trenchant lamella), which arc 

 sometimes narrow and become incorporated in a small basal mucro (fig. 19), or, 

 becoming more strongly developed, terminate abruptly near the base, formuig a con^nal 

 of knife-like edges encircling the rounded and smooth base (fig. 20). A still greater 

 modification of surface ornamentation is occasionaUy met with among members of this 

 group. In one ectosolenian form these riblets are reduced to four. These nre formed 

 by the bending over of the apertural rim of the neck, and pass down the sides in very 

 strong blunt ribs, which are of unusual width at their commencement, but, gradually 

 narrowing as they approach the base, project in the form of long thick spines. 



Lagena vulgaris, Williamson, var. striato-areolata, Nov. (Figs. 21, 21 a.) 



Shell subspherical, transparent, glassy, ornamented with a consideiablc numbor 

 (upwards of forty) of fine longitudinal striae, a few of which are continued partway up 

 the neck. Anteriorly the flask-walls pass into a very long, straight, smooth tube of 

 unusual length, and of equal diameter throughout. Walls minutely foraminated. 



This shell, through some accident, got broken after I had made a drawing of it 

 a misfortune which has proved beneficial, as it has disclosed the surface of the babe 



