i6 



conservation however, a' is situated less on the surface than a. In this way the facet thus 

 formed cannot be said to be absolutely dorsal, as it inclines towards the left lateral side. 



The facets B and B' (textfigg. 20, 21) are in this way not of the same shape, as B' is 

 smaller, more compressed. B is composed of the ridges a^, a'^, a, l> and the distal ridge e 



which is of exactly the same shape 

 n \a^ 2l^ ridge d. The facet B' consists 



of a'^ a'^^^ a\ b' and c and is 

 narrower at its base than B. We 

 do not doubt however, that this 

 difference in structure is abnormal 

 and that in living animals the 

 symmetry is maintained. 



The last facets C and C 

 (textfigg. 22, 23) are composed of 

 the ridges resp. a^'^ its contunu- 

 ation r, a very long irregularly 

 shaped ridge which is the margin 

 of the open hydroecial canal, and the posterior ridge which is verj- convex. 



C is composed of a'^^, its continuation c' and the same margin of the hydroecial canal on 

 the left side. The irregular shape is a little different and we find here a wing-like excrescence 

 at the superior part which resembles the same characteristic described by us for some very 

 tiny diphyid-Yik(t loose inferior nectophores (see p. ) (PI. II, figg. 13, 14, 15). 



The hj'droecial canal is quite open, from top to base, and this is the reason why the 

 space which would have been used for the fourth facet is entirely taken up by the cavity of 

 the hydroecial canal. We have looked in vain for any definite contours of the nectosac, and 

 the shape of the interior of this inferior nectophore is a mystery. This has been occasioned by 

 bad preservation. 



The description of the inferior nectophore shows certainly considerable resemblance to 

 the superior one of the same station although the mode of attachment must have been a very 

 singular one. The two nectophores are, to our opinion, new to the system. 



22. 



Figg- 19—23- 



Cknnip/iyes miillidcntata nov. gen. nov. spec. Facets of the infeiiov nectophore. 



Fig. 19: facet A, Fig. 20: facet B, Fig. 21: facet B', Fig. 22: facet C, Fig. 23: facet C. 



Figg. 19—23: 2 X- 



Fam. DiPHYiDAE Eschscholtz 29. 



I. Tribus Oppositae (Pr ay o m or phae) Ch. 



Subfam. Prayinae Ktill. 53. 



The material of the Prayinae in the Siboga expedition is very deficient. They are only 

 four loose nectophores, which through bad preservation have lost all the characteristics which 

 might have been useful towards their sjaecific determination. As it is, we can only give a very 

 brief description and a few sketches. 



