290 



APPENDIX. 



No. XL 



No. XL 



HYDROZOA. 



By George J. Allman, M.D., LL.D., F.R.S., etc. 



The elegant little, medusa here described was taken in the 

 towing-net by Captain Feilden in lat. 81° 44' N. It is re- 



I'iff. 1. Lateral view ; magnified. 



PTYCHOGASTRIA POLARIS. 



markable among hydroid medusge by its lobed umbrella- 

 margio, which thus presents a character belonging, to the 



