Hydromedusae.] SUBANTARCTIC ISLANDS OF NEW ZEALAND. 307 



The manubrium extends far down the subumbrella cavity, bearing a quadrate 

 mouth, at each of the perradial corners of which is a much-branched oral tentacle. 

 Each oral tentacle consists of 3 main stems rising from a short base ; each stem 

 gives origin to several dichotomous branches, and each final branch terminates 

 in a round knob of cnidoblasts. These oral tentacles spread out in all directions 

 within the subumbrella cavity. 



The mouth leads into a short stomach, whence the 4 radial canals originate, 

 at about one-half the height of the bell, and pass obliquely upwards towards the 

 roof of the umbrella, then turn abruptly downwards to the angles. 



The gonads lie along the ascending portion of these canals, and in the yoimger 

 individuals are limited thereto ; but in older specimens the gonads are continued 

 down the sides of the stomach as far as the mouth, and the 4 gonads may be so 

 extensive as to surround the stomach on all sides. Each gonad is really a double 

 structure, being traversed by a deep groove along its whole extent, so as to hang 

 down as a pair of lamellae from the underside of the canal. 



Dimensions. — Height, 12-14 mm. ; breadth, 7-9 mm. 



Colour. — The umbrella is trarsparent and colourless ; the gonads a pale pinkish- 

 brown ; the tentacles reddish. 



Locality. — Auckland Island : Musgrave Harbour (W. B. B.) ; Norman's Inlet 

 (C. Chilton). 



Remarks. — Haeckel* describes and figures H. madoviana, which occurs at the 

 Falkland Islands. This differs from the present species in its smaller size, and in 

 the fact that the manubrium originates high up in the cavity of the umbrella, so 

 that the upward course of the radial canals is not nearly so marked. 



Agassizf figures the medusa of Bougainvillea suferciliaris from the American 

 coastal waters. This resembles the Auckland Island species in the general arrange- 

 ment of parts, but the shape of the animal is more nearly spherical. It may be 

 mentioned, however, that those of our specimens that are preserved in alcohol have 

 a more spherical form than those in formol. 



It is, of course, impossible to state to what species of hydroid our medusa 

 belongs. The only member of the family that has been recorded from our shores is 

 Hemitheca, Hilgendorf,J which is represented by a single species, H. intermedia ; 

 but whether this occurs at the Auckland Islands is imknown. 



Order LEPTOMEDUSAE. 

 Fam. EucopiDAE. 

 Subfam. Obeliinae. 

 Phialella, Browne, 1902. (Plate XII, figs. 3-6.) 



Depressed bell-shaped ; the margin of the umbrella bears numerous hollow 

 tentacles, the bases of which are much enlarged, forming spherical bulbs, in which 

 there is no definite ocellus — ^that is, no pigment is present in the preserved specimens. 



* Haeckel, " Das System der Medusen," 1879, p. 90, pi. v, figs. 1, 2. 



t A. Agassiz, " The North American Acalephae," lUus. Cat. Mus. Comp. Zool., Harvard, ii, 1865, 

 p. 153. 



t F. W. Hilgendorf, Trans. N.Z. Inst., xxx, 1898, p. 202. 



