476 Mr. E. T. Browne on the Medusce 



Genus ToxORCHis, Haeckel, 1879. 



Generic character. — Laodiceidse with six main radial canals, 

 each one widely forked or with lateral branches. 



Toxorchis arcuatus, Hseckel, 1879, p. 157, Taf. ix. figs. 0-8. 



This species has only been seen by Hasckel. His figures 

 show that each radial canal is widely forked, with gonads in 

 the fork of the canals. The margin of the umbrella is 

 provided with twenty-four tentacles, and between every two 

 tentacles there are a cirrus and a cordylus. The basal bulbs 

 of tentacles have ocelli, 



.Distribution. North Atlantic; Canary Is. {Hrjeckel). 



It is probable that the genus Cladocanna, HaBckel (1879, 

 p. 160), will ultimately become a synonym of Toxorchis. 

 There are two species, G. thalassina (Pdron, 1809), whicii 

 has not been well described, and G. polycladia^ which 

 HjBckel has described but not figured. The latter species 

 has six radial canals with several lateral branches, each of 

 which is again dichotomously divided. The tentacles are 

 very numerous and between them are cirri and marginal clubs. 

 If the marginal clubs turn out to be cordyli, then I would 

 suggest that tiie species be placed in the genus Toxorchis. 

 Maas (1904:) considers G. polycladia to be identical with 

 G. thalassina, and doubtfully refers it to the genus Toxorchis. 



Genus Melicertissa, Hjeckel, 1879. 



Generic character. — Laodiceidfe with eight radial canals, 

 without lateral branches. 



This genus Haeckel placed in the Thaumantidje, in the 

 subfamily Melicertida3^ containing genera with eight canals. 

 This subfamily will probably disappear on the completion of 

 the revision of the Thaumantidaj. 



Melicertissa clavigera, Hajckel, 1879, p. 135, Taf. viii. 

 figs. 8-12. 



This is another species which has only been seen by 

 Hgeckel. It has only eight tentacles, and between every two 

 tentacles there are three cordyli but no cirri. The basal 

 bulbs of the tentacles and cordyli have ocelli. 



.Distribution. North Atlantic : Canary Is. (Hceckel). 



