DIPHYES BOJANI. 253 



more strongly serrate than large ones; such is the case in the small "D. gegen- 

 bauri." 



From this evidence the only conclusion, it seems to me, is that D. gegen- 

 bauri, D. tnalayana, and D. indica represent three successive stages in the devel- 

 opment of a single species. My reasons for uniting them with Doromasia bojaui 

 and D. pidoides are given above (p. 245). 



Diphyes bojani, though it varies in general form almost as much as Diphyop- 

 sis dispar, is easily distinguished from other Pacific Diphyids by the following 

 characters: — The anterior nectophore is slender, pointed at the apex, truncate 

 at the base; there are five prominent ridges except at the apex in some indi- 

 viduals, and as noted, these are often expanded to form "wings" in the upper 

 one third of their course; the serrations of the ridges are everywhere variable, 

 especially so at the apex; the nectosac reaches nearlj^ to the apex. 



The hydroecium is pointed at the top, and reaches nearly to one third the 

 height of the nectosac. The somatocyst is fusiform, and its form and length 

 very constant. Both dorsobasal and laterobasal teeth are large, though variable 

 in form as already noted. The dorsobasal wall of the hydroecium, below the 

 bell opening, is entire, its margin slightly concave, and the teeth serrate. The 

 lateral basal margins are concave in small specimens (Plate 12, fig. 1) as described 

 by Lens and Van Riemsdijk {" D. gegenbauri"), straight in large ones (Plate 7, 

 fig. 3), and serrate in all. 



Posterior nectophore. The entire specimens afford an opportunity to describe 

 the inferior nectophore. In general outline (Plate 10, fig. 2) it much resembles 

 the corresponding nectophore in Diphyopsis dispar (Plate 10, fig. 1), and as in 

 the latter the two lateral flaps which cover the hydroecium remain separate, 

 instead of uniting to form a closed canal as they do in Diphyes appendiculata 

 (Plate 10, fig. 6). It is easily distinguished from D. dispar by its more slender 

 form, and by the pronounced serration of the two lateral basal edges and 

 lateral teeth of the hydroecium, regions which are entirely smooth in dispar; 

 in its basal region, and in its serration, it resembles the corresponding nectophore 

 of D. steenstrupi (Gegenbaur, '60), a species with which bojani may finally be 

 united (p. 246). The measurements of an entire colony are superior nectophore, 

 length 12 mm., inferior nectophore, 9 mm. 



Cormidia. The most advanced groups of appendages (Plate 11, fig. 5). 

 consist of siphon, tentacle, bract, and gonophore. As Lens and Van Riems- 

 dijk ( : 08) have pointed out, there is no special nectophore. The bract with two 

 prominent basal teeth, is of a characteristic form. 



