Aiifif raliiia Hydro ids. 83 



The hydrotlitTUc' as seen in tlie broader aspect, are wider-based 

 than any other form except 0. inncrogona, with the wall often con- 

 siderably thickened at the border, and continuing fairly thick 

 down to the base; oi- in some cases the thickening is confined to 

 the upper part, foi-ming a convex l)and like that of 0. macrogond, 

 but not so pronounced. The narrow aspect is funnel-shaped, with 

 no thickening except a very slight one in the su]>marginal region. 

 The border generally rises a little above the thickened part, and is 

 distinctly everted. 



The gonangia are broad, but rather short, theii- lieight averaging 

 a})out 1.3 mm., and their width .90. They are ovate, truncate 

 above, and nmch compressed ; in the broad view the edges are un- 

 dulated, curving inward near the top, and then outward, forming 

 where they meet the top blunt angles, w-hich are usually produced 

 someW'hat outward and upward. The summit of the gonangium 

 is slightly concave or nearly flat, and so nari-ow that an end view- 

 would be lanceolate rather than elliptic. Irregidar forms are found, 

 but most of those examined were normal. Two gonozooids are con- 

 tained, pretty closely packed, the lower one larger in proportion to 

 the upper than is usually the case, and lying obliquely to it. The 

 only gonangia seen contained male gonozooids. The eight otocysts 

 of the medusa were very distinct. 



A very close affinity exists between the present species and 

 Eucopella campanularia Von Lendenfeld (which is discussed under 

 O. coinpressa). The principal difference is in the form of the gon- 

 angia, which are distinguished from those of E. campanularia by 

 the broader lower portion, the undulated outline, and particularly 

 by the prominent superior angles. 



SiLiouLARiA, Meyen. 



H i/panfhea, Allman. 



Eucopella, in part, Von Lendenfeld, Hartlaub. 

 Allman's description of tlie genus Hypanthea is as follows : — 

 " Hydrothecae pedunculate, inoperculate, with walls enormously 

 thickened, and so far encroaching upon the cavity as to render im- 

 possible the complete retraction of the hydranth. Gonosome — 

 ^Gonangia enclosing fixed sporosacs." The species were further char- 

 acterised by the possession of bilateral hydrothecae, with oblique 

 apertures. A more recently described species, however,- — .S'. diver- 

 gens Ha]-tlaul> — differs from all the others in having the hydrotliecae 

 regular, with a large cavity, and apparently resembling those of 



