192 NUTTING [174] 



OBELIA BOREALIS sp. nov. 

 (Plate XIX, figs. 4, 6.) 



Trofhosome. — Colony sometimes attaining a height of eighteen 

 inches, but usually much shorter ; stem not truly fascicled, although 

 several stems may be interwoven, exceedingly long and slender, sinu- 

 ous, giving off lateral branches in pairs on proximal portion and more 

 often singly on distal portion ; branches with a strong tendency to ver- 

 ticillate arrangement, forming oblique angles with the stem and 

 divided into numerous branchlets in a flabellate manner. Pedicels 

 short and completely annulated, or long and annulated only at ends, 

 set on broad shoulders of the stem. Hydrothecae funnel-shaped, the 

 sides usually straight, aperture with an even rim. Hydranths not well 

 preserved in specimens examined. 



Gonosome. — Gonangia borne in axils of branches and branchlets, 

 oblong-ovate, truncated above, having a collar in mature specimens ; 

 aperture apparently very large, pedicels strongly annulated. The 

 gonangia of the specimens examined were filled with developing 

 medusae of the regular Obelia type. 



Distribution. — Yakutat, Alaska (Harriman Exped.). 



This fine species is related to O. Jiabellata, but the hydrothecae are 

 much deeper than in O. Jlabeliata, in which they are sub-triangular in 

 outline. It also bears some resemblance to O. com?)iiss2tralis, which, 

 however, is a much more delicate species, with smaller and more 

 campanulate hydrothecae. 



OBELIA DUBIA sp. nov. 

 (Plate XX, fig. I.) 



Trophoso7ne, — Colony attaining a height of about ^ inch ; stem 

 sparingly branched, the main stem and larger branches sinuous or 

 slightly geniculate, giving forth pedicels singly or in opposite pairs at 

 the bends. Pedicels rather long and annulated throughout, the stem 

 also more extensively annulated than in most species of the genus. 

 Hydrothecae very large, deep, tubular, with very shallow undulations 

 around the margin, from between which lines run down for a short 

 distance on the surface of the hydrothecae. 



Gonosome. — Unknown. 



Distribution. — Orca, Alaska (Harriman Exped.). 



This species bears some resemblance to O. bidentata Clark, found 

 on the New England Coast, but differs in the nature of the hydrothe- 

 cal teeth which are mere sinuosities, instead of being mucronate with 

 two denticles each as in the latter species. 



