﻿MR. F. W. O. RYMER JONES ON SOME JAVAN DEEP-SEA LAGEN^. 57 



L 

 I 



is short, bounded by the transparent " keel," which extends about one third down the 

 sides, where it disappears, and again becomes apparent round the extreme base in a very 

 narrow ridge. Internal tube bent towards one side, and ending halfway down in a 

 trumpet mouth. Shell-walls smooth and semitransparent, tlie foramina being confined 

 to the margins, where they cluster and form a wide band. 



r 



In some of the entosolenian and marginate structures two wide supplemental " plates " 

 are observable, one on each side of the circumambient keel, but confined to the base only. 



!Fig. 29 is a very symmetrical bottle-shaped form, provided at the centre of the base 

 with a small mucro. External neck wide and well developed, with a thick lip round 

 the orifice, from either side of which arises tlie marginal border, and passes down to the 

 base. Walls bulging, and coarsely granulated. Hue pale brownish-yellow. No in- 

 ternal tube. . . 



Pigs. 30, 31, appear to be essentially the same as the form depicted by Messrs. Parker 

 and Rupert Jones (Monogr. pi. xvi. fig. 12). The walls are very glassy and smuuth, 

 and the peripheral margin translucent. In some examples the anterior portion is very 

 pointed, but wide and rounded at the base, to which end the marginal keel is sonicthncs 

 confined, while in others the shell becomes more oval, and the transparent border passes 

 entirely round in a moderately wide and thickened band. In fig. 30 the bhell bccomuii 

 more lenticular, the flattened margin bemg well developed and very trenchant. The walls 

 are sometimes considerably bulged, as is seen in the form delineated in fig. 31, which repre- 

 sents a similar shell as seen from a three-quarter basal view. The internal tube is very 



vari able. 



A remarkable modification is observable in fig. 32, the shell being compressed and thc^ 

 walls considerably bulged, while their exterior is covered with numerous short acicular 

 spines ; the external neck is very slender ; and the periphery of tlic shell is encompassed 

 by two narrow keels of transparent shell-substance. 



Lagex\a vulgakis, Williamson, var. radiato-marginata, Parker and Rupert Jones. 



(Pig. 33.) 

 Shell very compressed, entosolenian, encircled at the periphery by a thickened trans- 

 parent rim. Shell-walls smooth, semitransparent, the pscudopodial passages taking an 

 oblique radial direction. These canal-pores are more strongly developed in the form 

 from the Australian coral reefs, depicted by Messrs. Parker and Rupert Jones (Monogr. 

 pi. xviii. fig. 3). 



Lagena vulgaris, Williamson, var. spinicosto-margimta, Nov. (Tigs. 34-3(5.) 



Shell very closely resembling the preceding form in general outline ; but the waUs are 

 somewhat more bulging, and the pscudopodial canals pass directly from within outwards. 

 The thick marginal" rib is still present, and gives rise to from two to four blunt or acicular 

 spines, which project from the basal portion of the shell. In fig. 31 the spmes arc 

 blunt and only two in number, projecting from the point of junction of the side waU 



XXX 



