FROM A DREDGING IN THE WEDDELL SEA. 
699 
Syringocnemidse. 
Syringocnema, Taylor. # 
Syringocnema gracilis, sp. nov. (PI. V, fig. 49 ; PI. IV, figs. 43-48.) 
The genus Syringocnema was instituted for certain South Australian forms of the 
Archseocyathinae which were very exceptional in structure. The outer and inner 
walls are not connected by septa, tabulae, or dissepiments, but by a series of almost 
horizontal hexagonal tubes which had porous sides. Only one species was recorded, 
and no other form has since been discovered. Among the Weddell Sea material, 
however, four specimens were discovered which are indubitably referable to this 
genus. It happens that the preservation is not so good as in most of the other 
forms, but the essential characters can easily be demonstrated. The only rather 
unsatisfactory part is connected with the porous structure of the walls of the 
horizontal tubes. 
A transverse section of the type (PL IV, fig. 43) is, at first sight, not unlike an 
ordinary Archaeocyaihus , but should the section be slightly oblique (PI. IV, fig. 44) 
a very characteristic appearance is imparted to the whole cup. The apparent septa 
are seen to diverge and then converge in pairs. Where they diverge again from 
each other a cross wall joins them. The explanation of this phenomenon is given by 
oblique or tangential longitudinal sections (PL IV, fig. 47). Here the whole area of 
the section is covered by hexagonal cells, each being a section of one of the tubes 
which cross the intervallum. In longitudinal radial section it may be noted that 
the tubes are not absolutely horizontal, and that they bend down at their inner 
ends, and hence the apparent vesicular zone near the inner wall in some sections 
(PL IV, fig. 44, a). 
Referring back to fig. 43, it will be noticed that the outer wall has not the regular 
outline usually seen in other Archseocyathinse, but that each tube has a curved end 
convex outwards. In some cases (p, p, p) the end is more abrupt and projects 
further from the general line, so that an irregular toothed outline is imparted to the 
exterior. This again is best explained by longitudinal sections. In Pl. IV, fig. 45, 
such a section is shown. It is oblique, so that it cuts deeper into the tubes at the 
right-hand side, and is closer to the outer surface on the left. Proceeding from right 
to left across the figure, we notice progressive thickening of the walls of the tubes, 
and a consequent decrease in the lumen, until at the left-hand side the lumen is 
rounded instead of hexagonal, and the walls seem very thick. Now in transverse 
section (fig. 44) the walls are not much thickened, the apparent thickening being due 
to the contraction of the mouth of the tubes towards the exterior, so that the pore 
stands on the apex of a small conical projection from the general level of the wall 
(text-fig. 1 b and c, o.p.). The surface, if it could be exposed, would thus be covered 
by small papillae, each with a pore on its apex. In Syringocnema favus, Taylor, the 
* Mem. Roy. Soc. South Australia, vol. ii, part ii, 1910. 
