476 Mr. E. T. Browne on the Medusce 



Genus Toxorchis, H^ckel, 1879. 



Generic character. — Laodiceidse with six main radial canals, 

 each one widely forked or Avith lateral branches. 



Toxorchis arcuatus, Hteckel, 1879, p. 157, Taf. ix. figs. 6-8. 



This species has only been seen by Hackel. 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. 



Distributioyi. North Atlantic; Canary Is. (^Ilcechel). 



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

 p. 160), will ultimately become a synonym of T'oxorchis, 

 There are two species, C. thalassina (Pdron^ 1809), which 

 has not been well described, and C. polycladia, which 

 Hseckel 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 tlieni are cirri and marginal clubs. 

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

 suggest that the species be placed in the genus Toxorchis. 

 Maas (1904) considers C. iwlycladia to be identical witli 

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



Genus Melicertissa, Hseckel, 1879. 



Generic character. — Laodiceida^ with eight radial canals, 

 without lateral branches. 



This genus Hseckel placed in the Thaumantidse, in the 

 subfamily Melicertidse, containing genera with eight canals. 

 This subfamily will probably disappear on the completion of 

 the revision of the Thaumantidse. 



Melicertissa clavicfera, Hseckel, 1879, p. 135, Taf. viii. 

 figs. 8-12. 



This is another species which has only been seen by 

 Ha^ckel. It has only eight tentacles, and between every two 

 tentacles there are three cordyli but no cirri. Tiie basal 

 bulbs of the tentacles and cordyli have ocelli. 



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



