JELLYFISHES AND HYDROIDS 35 



forty tentacles. The veil-like lips around the moutli form long, 

 graceful curtains often two and one-half feet in length. This me- 

 dusa can be at once distinguished by its amber-pink coloration, and 

 the sixteen spoke-like areas of reddish specks upon the convex side 

 of the disk. There are eight sense organs, each containing a 

 spherical mass of concretions. These are situated at regular inter- 

 vals within notches at the disk-margin. 



The Milky Cross, (Staurophora laciniataj, is abundant along 

 the Atlantic coast north of Cape Cod, during the summer months, 

 and is occasionally seen along our coast in spring The appear- 

 ance of a milky-colored cross is produced by the large cruciform 

 mouth bordered with veil-like frills containing the reproductive 

 organs. It is from four to eight inches in diameter. There are 

 numerous little eye spots at the base of the tentacles, upon the bell 

 margin. 



The Thimble-Jelly, (Melicertum campanula J. This little Arctic 

 jellyfish resembles a large thimble of clear jelly-like substance 

 with eight, yellow, radial canals extending from the stomach at the 

 centre of the concave side of the thimble to the edges forming, so 

 to speak, the spokes of a wheel. The edge of the bell is provided 

 with numerous tentacles. It is exceedingly abundant until mid- 

 summer, north of Cape Cod, but is 

 found on our coast only in the spring. 



( Gonionemus murhachii, Fig. 11). 

 This interesting little jellyfish is famil- 

 iar to all who study at the Woods Iloll 

 Laboratory, for it is very abundant in 

 the Eel Pond at that place. The bell 

 is transparent, somewhat flatter than a 

 hemisphere, and when full grown it 

 becomes about one inch in diameter. 



About eighty long, flexible tenta- 

 cles arise from the side of the bell near ^^- ''^ f "yj!*^- fZ'7T" 



tnurbac/ni, Woods Holl, Mass. 



the rim. Each of these bears a sucker- 

 like disk upon its upper side near its extremity, and the extreme tip 

 of the tentacle bends sharply at right angles. The tentacles are cov- 

 ered with wart-like clusters of minute thread-cells each containing a 

 coiled tube which can be turned inside out as we might do with the 



