APPENDIX. 171 



9. PAGE 15. Pleurobrachia rhodactyla, Agassiz. This is one of the 

 numerous free-swimming marine animals, belonging to the Ctenophores. 

 A group of the sea-jellies which have the pretty rows of paddles adown 

 their long diameter. They are usually about a pigeon's-egg in size, are 

 oval, and in their element almost invisible, so colorless and transparent 

 are they. A close inspection shows the paddles to be iridescent. 



10. PAGE 15. Idya roseola, Agassiz. Another form found near the 

 shores of Nahant. 



11. PAGE 16. The Physophoridce include the interesting forms, Phy- 

 salia (Portuguese Man-of-War), Porpita, Vellela, etc. The first named 

 indicates the character of the group, as its fleshy mass is surmounted by 

 a beautiful bladder-like float, a mere bubble of membrane. These forms 

 are not often seen out of tropical waters. 



12. PAGE 16. The term zooids is applied to the mass of tentacles 

 and other fleshy parts of the Physophorce. The long, extensile feelers are 

 for prehension; others aid in locomotion, and some are reproductive; 

 others are feeders for the entire colony. Thus it will be seen that these 

 creatures are in a sense compound animals. 



13. PAGE 24. Alcyonarian corals from an order in the class 

 Aclinozoa. 



14. PAGE 24. Professor Moseley, of the " Challenger " expedition, 

 was enabled to examine the light from these beautiful forms by the aid 

 of the spectroscope, and found that it consisted of red, yellow, and green 

 rays only. 



15. PAGE 25. Acanella normani Verril. A pretty soft coral, which 

 has been dredged off the New-England coast by the fish-commission. 

 This is a revelation to science, as no one was ready to believe that such 

 forms, so common to the tropical regions, would be found where they 

 were. The Gulf Stream runs so close to the North-eastern States, it will 

 not, on reflection, seem strange that some creatures common to the 

 warmer waters may find a home there. 



16. PAGE 25. Primnoa resida. 



17. PAGE 25. Paragorgia arborea. 



18. PAGE 26. Pennalulidce. The name of a family of marine ani- 

 mals, which includes the Umbetlularias, Veretillum, etc., the last highly 

 phosphorescent. 



