218 ABYLA LEUCKARTII. 



therefore especially valuable. The posterior nectophore in both instances was 

 still entirely enclosed in the hydroecium, being attached to the base of the stem 

 by a long pedicular canal. But when detached and studied each proved to be 

 far enough advanced in development to show the general characters, (Plate 13, 

 fig. 5). The posterior nectophore is comparatively long and narrow (Plate 13, 

 fig. 6) and laterally compressed; its general appearance suggests the correspond- 

 ing structure in Diphyes bojani (p. 253). There is a well-marked dorsal ridge 

 extending from apex to base, and on each side a lateral ridge arising at about 

 the level of the top of the nectosac. Each of these ridges terminates in a large 

 triangular serrate tooth, and there is also on either side a tooth at the dorsobasal 

 margin of the hydroecium, the left hand one being much the larger. The 

 hydroecial groove, as in D. bojani, is open throughout its length, but it is covered 

 over by two lateral wings. A characteristic feature is that the left wing bears 

 a secondary flap with undulating margin, on its inner face near the base, while 

 the right wing bears two such flaps (Plate 13, fig. 7). The nectosac is of the 

 usual form, nor do its canals present any features of special interest. 



The discovery of a group of appendages, rather far advanced in development, 

 is likewise important, not only because the structiu'e of the cormidia was pre- 

 viously entirely unknown, but especially because the structure of the somato- 

 cyst of the bract suggests that it may be an early stage of the interesting Eudoxid 

 known as "Ceratocymba." In the present example the somatocyst is of 

 the "Amphiroa" type, consisting of a descending sac, and two more slender 

 diverging canals; and the former, seen in side view, is curved upward sharply 

 near its free end. A comparison between it and the various figures of Cerato- 

 cymba (Bedot, :04, Lens and Van Riemsdijk, :08) as well as with the "Alba- 

 tross" specimens of the latter (Plate 15, fig. 3, 4) shows that the resemblance 

 between the two, in so far as this character is concerned, is an extremely close 

 one. The general form of the bract is not yet sufficiently advanced to show its 

 final outline, but its large descending scale-like portion resembles in its general 

 form and proportions the corresponding region in Ceratocymba. It is already 

 divided into three facets, a dorsal, and two laterals, and of the latter the right 

 hand one is already the larger, a character which foreshadows the asymmetry 

 of the bract in the free "Ceratocymba" Eudoxid. The apical portion of the 

 bract, still divided for the passage of the stem, corresponds to the dorsal facet 

 of the latter. 



As to the arrangement of its ridges nothing can yet be said. There are two 

 gonophores, one well developed (apparently cf), one still merelj- a bud. The 



