﻿52 MR. F. W 



ON SOME JAVAN DEEP-SEA LAGEN^ 



son pi. 1. fig. 6), or gently rounded (fig. 12), presenting very variable and elegant shapes 

 of wat^r-carafes, vases, &c. The extremity of the neck is generally surrounded Ly a 

 thickened marginal rim, which occasionally curves over, forming a deep lip (fig. H). 



In the glohtilar structure depicted in fig. 11, there projects from the centre of the lase 

 what appears to be an extremely short and narrow infernal tube, which apparently com- 

 municates with the exterior. 



A similar tube I have also observed in a form of L. striata, and also in L. jperhm- 

 marginata (fig. 47) ; but, owing to the extreme minuteness of this tube and the smallness 

 of the shell, its presence might easily be overlooked. 



In the symmetrical form, of which fig. 13 is a copy, the stolon-tube is produced into a 

 well-formed straight central neck, the rini of which becomes thickened, and is ornamented 

 with a few slender recurved spines round its external margin. 



Lagena vulgaris, Williamson, var. glacialis, Nov. (i'ig. 14.) 



Shell, symmetrical, amphora-shaped, widest just above the middle, from which it 

 tapers towards the base, where it is bluntly rounded. Anteriorly it contracts into a pro- 

 longed wide neck, which in this specimen appears to be broken. Shell- w^all transparent 

 and glassy, composed of irregular plates of shell-substance, which crowd together and 

 overlap each other like a field of broken ice. 



r - -I ■ 



No internal tube. 



f- 



Lagena vulgaeis, var. semistriata, Williamson. (Fig. 15.) 



Shell fiask-shaped, more or less elongated, resembling the typical form in its numerous 

 gradations of contour. The .posterior portion is ornamented with a variable number of 

 fine striae, which are sometimes very feeble, or, becoming more apparent, pass up the 

 exterior, not unfrequently as high as the upper third of the structure. In some the 

 striations project beyond the base, forming a coronal of sharp spikes, or the shell is pro- 

 vided with a small mucro. The walls vary considerably in different individuals as 

 regards perforation and hue, in some being densely foraminated and of a dirty white 

 colour (fig. 15), while in others they are transparent and glassy and apparently imper- 

 forate. Anteriorly the shell tapers into a more or less elongated neck, which is sur- 

 mounted at the orifice by a ** turned " rim. This neck is generally smooth ; but in some 



rieties, such as the Oolina striaticollis of D'Orbigny (Yoy. dans. I'Am^r. Merid. roram. 

 p. 21, tab. 5. fig. 14), it is ornamented with a neat spiral. This peculiar style of decora^ 

 tion, however, is not confined to these forms, being observable in L. striata (fig- 18)^ ^^^ 

 also m L. sulcata (fig. 26), where it becomes greatly developed. 



Fig. 15 somewhat resembles the smooth L. vulgaris, var. clavata, of Williamson; bu 

 the base is not so conical. These semistriated forms unite the smooth with the striated 

 vaneties, and are most probably but incipient growths of L. striata. 



T ^ 



lAGENA vuLOARis, Williamson, var. s<m<„, Montagu. (Kgs. 16-20.) 



The general shape of these flask-Uke forms is subslobular or widely elliptical, some- 



