BATHYMETRINAE 167 



pinnule, is of 17 segments, 6 mm. long. The ambulacral furrow is absent from the lower 

 genital pinnules but present on the outer. The distal pinnules are of about the same 

 number of segments and length as the last genital, Pg . 



The elongated segments of the oral pinnules are up to three times as long as broad ; 

 those of the lower genital pinnules may be a little more elongated ; those of the outer- 

 most pinnules are shorter, up to about twice as long as broad. 



The disk cannot be seen. 



Sacculi are fairly conspicuous, more numerous and more regularly arranged on the 

 outer than on the genital pinnules. There are no side- or cover-plates along the pinnule 

 ambulacra. Some of the tentacles have within them numbers of rod-like spicules 

 (Fig. 10^). 



The specimen is of a pale straw colour in spirit except for the syzygial pairs which 

 are dusky and stand out as dark bands along the arms. 



This new variety, like the parent species (see below), is brood-protecting: the embryos 

 undergo their development in pouches alongside the ovaries. The pouches are always 

 on the aboral side of the pinnule, nearest the arm and the outside. The ovaries and 

 brood-pouches of the middle genital pinnules lie along the third to fifth segments. 

 Both can be seen at the same time from the outside and their walls are so thin that their 

 contents can be seen through them (Fig. 10 e,f). The ambulacral furrow of the outer 

 genital pinnules lies along the dividing line on the ventral side. I have not been able to 

 see the pore which must exist in the septum dividing ovary and brood-pouch. The wall 

 of each pouch is split open for the whole of its length exposing the embryos within. 

 There are ten or eleven in each pouch; they occur in one layer and each is lightly 

 attached to the floor of the chamber, the dividing septum, by an extremely thin mem- 

 brane. They are roughly spherical, except that one end is strongly flattened to form the 

 suctorial disk, from 0-21 to 0-24 mm. in diameter, considerably smaller than those of 

 Etimorphometra concinna, and all appear to be at the same stage of development. The 

 vestibulum is clearly marked. There are four bands of cilia, one lying around the edge 

 of the suctorial disk; I cannot see traces of a more anterior band. The skeleton consists 

 of about 18 stem-joints and a larger terminal plate and often large but openly branching 

 plates, five orals and five basals, which may be nearly in contact with one another. 



The single female from St. 1948 is very much smaller than that from St. 156 and its 

 arms are even less complete; one of the longest is of 21 brachials and 10 mm. long. 



The centrodorsal is a moderately low and slightly rounded cone. The dorsal pole is 

 large, bare and rounded. The arrangement of the closely crowded cirrus sockets appears 

 to be in part in columns and in part in alternating rows. 



Cirri L, 12-17. The apical have the smaller number of segments and are con- 

 siderably shorter than the peripheral. The cirri closely resemble those of the specimen 

 from St. 156 except that they are smaller and that the opposing spine is much smaller 

 or it is obsolete. 



The radials, primibrachs and brachials resemble those of the specimen from St. 156. 



