﻿64 MR. F. W. O. RYMER JONES ON SOME JAVAN DEEP-SEA LAGENiE 



with the variety L. distoma-polUai Parker and Rupert Jones, restricting the designation 

 X. apiculata of Eeuss to those structures which, though more or less produced and 

 pointed at the hase, are still unprovided with an aperture *. 



Lagex A VTJLGAEis, Williamson, var. cf/s^oma-po/Z^a, Parker and Hup crt Jones. (Pigs. 53-57.) 



This elongated distomatous variety, which is generally smooth, scmitransparent, and 

 finely foraminated, is suhject to considerahle modification of contour. Most commonly 

 it is a slender fusiform shell, tapering towards each end to a narrow tuhe, one of which 

 is sometimes prolonged into a well-formed neck, with a flattened rim encircling the 

 aperture, the other tuhe, though occasionally long, not unfrequently being very short 

 and undeveloped. 



In some forms (fig. 56) the greatest width is in the middle of the shell, where it 

 becomes decidedly angular ; and the axis of the shell in this particular form is slightly 

 curved. Messrs. Parker and Rupert Jones figure a somewhat similar example from the 

 Red Sea and Australia, which, however, is perfectly straight (Monogr. pi. xiii. fig. 8). 



Sometimes the greatest diameter is removed nearer one end, and the shell becomes 

 more or less amphora-shaped (Messrs. Parker and Rupert Jones, Monogr. pi. xiii. fig. 21), 

 several examples of which occur in these soundings ; or the walls taper equally towards 

 each end, both the necks bemg equal and very slender (fig. 55). 



An elongated smooth form is depicted in fig. 53, the anterior being provided with a 



fissurine orifice, communicating with the interior through a straight internal tube, while 



the base gradually tapers into a second narrow infundibular prolongation of considerahle 

 length. 



A rather interesting modification of the distomatous series is observable in fig. 54. 

 In this form the chambered portion, or shell proper, is more or less elongated, narrowing 

 at ei^ther end, the upper part passing into a very long and neck-like extension, which in 

 fig. 54 is almost as wide as the ilask-shaped body. The lower end of the shell is also 

 shghtly drawn out, and fm-nished with a basal aperture, which in some forms is equal in 

 diameter to that at the opposite end, but in fig. 54 is much smaller. In the figiu-e here 

 delmeated this long tube appears broken; and in a somewhat similar structure in my 

 cabmet, which is even more elongated, though the neck is slightly narrower in diameter, 

 both ends seem to be defective, so that how far it extended when entire I am unable to 

 say. Shell-waUs smooth and semitransparent 



A still more remarkable form is depicted in fig. 57. It consists of an extremely long, 

 smooth, and symmetrical distomatous structure, having the appearance of two simple 

 flasks which have sprung from the base of a third in the same axial line, the shell-walk 

 bemg continuous throughout. The largest of these portions has the form of a long, 

 narrow, trunc^ated cone, tapering gradually towards one end almost to the extremity, at 

 the apex of which is situated a very smaU circular orifice. At the « basal " end of thi^ 



therefore the ^.,1..Z^T.: ., I ''.f™ ""* """ ""> '^7 striated diatomatou, fonns in this soundmg, f 



organism 



above-describea sheU and aU the succeeding 



snbyarieties of that 



