fieferences. 
These references are, in so far as possible, to works in the English lan- 
guage wherein one may find a more elaborate description than is possible in this 
little book. They usually refer to the best published drawings, or figures, of the 
several species. As a rule, the following references relate to species only. Refer- 
ences to literature concerning families and orders will be found throughout the text. 
JELLYFISHES AND HYDROIDS. 
Portugese Man-of-War (Physalia arethusa)—-Agassiz, L., Contributions to Nat. Hist. 
of the U. 8., Vol. IV, Pl. 35. Haeckel E., Siphonophorz of the Challenger 
Expedition, Challenger Reports, Zoology, Vol. XXVIII. 
Porpita linnaeana—Agassiz, A., Memoirs Museum Comparative Zoology, Harvard, 
Vol. VIII, No. 2. 
Velella mutica—Agassiz, A., Memoirs Museum Comparative Zoology, Harvard, 
Vol. VIII, No. 2. 
Passion-Flower Hydroid (Thamnoenidia spectabilis)\—Agassiz, L., Contributions 
to Nat. Hist. of the U.S., Vol. IV, Pl. 22. 
Eel-Grass Hydroid (Pennaria tiarella)—Arnold, C. F., Sea Beach at Ebb Tide, p. 124. 
Hargitt, C. W., American Naturalist, Vol. XXXIV, p. 387, Pls. 1-4. 
Sea Blubber (Cyanea arctica)—Agassiz, L., Contributions to Nat. Hist. of the U. S., 
Vol. III, Pl. 3, 5, 10,1860. Agassiz, E. C. and A., Sea-side Studies, p. 38. 
Speckled Jellyfish (Dactylometra quinquecirra)—Agassiz and Mayer, Bull. Museum 
Comparative Zoology, Harvard, Vol. XXXII, 1898. 
Milky Disk (Aurelia flavidula)—Agassiz, E. C. and A., Sea-side Studies, p. 42. 
Arnold, C. F., Sea Beach at Ebb Tide, p. 137. Agassiz, L., Contributions to 
Nat. Hist. of the U.8., Vol. III, Pls. 6-11b, Vol. IV, pp. 10, 160. 
Milky Cross (Staurophora Jaciniata)—Agassiz, L., Contributions to Nat. His. of 
the U.S. Acalephz North America, Part 1, Pl. 7, 1849. 
Thimble Jellyfish (Melicertum campanula)—Agassiz, E.C. and A., Sea-side Studies, 
p. 63. Agassiz, A., North American Acalephe, p. 130. 
Gonionemus murbachii—Murbach, L., Journal of Morphology, Vol. II, 1895. Yerkes 
and Ayer, American Journal of Physiology, Vol. 1X, p. 279. Perkins, H. F., 
Proceedings Academy Natural Science, Phila., Nov., 1902. 
Sea-Plume Hydroid (Obelia, Eucope)—Agassiz, L., Contributions to Nat. Hist. of the 
ULS., Vol. IV, Pl. 33. Brooks, W. K., Handbook of Invertebrate Zoology, p. 31. 
