120 



CCELENTERATA 



1. Aglaura Peron and Lesiieur. Gonads 8, on manubrium; 8 litho- 

 cysts: 1 species. 



A. hemistoma Per. and Les. Medusa cylindrical or octagonal, 4 mm. 

 high, truncated above, transparent; radial canals 

 8 ; tentacles numerous, veiy short ; 18 linger-like 

 gonads suspended from the manubrium: cosmo- 

 politan. 



2. Aglantha Haeckel. Gonads 8, on subum- 

 brella : 3 species. 



A. digitalis (0. F. Miiller) (Fig. 201). Me- 

 dusa elongate, miter-shaped, 30 mm. high and 15 

 mm. wide, with 8 radial canals, pinkish and trans- 

 parent; tentacles numerous; gonads elongate and 

 suspended from the upper end of the subumbrella; 

 mouth with 4 everted lips: North Atlantic; often 

 common on the New England coast. 



3. Persa McCrady. But 2 gonads present, 

 which are thick and elongate and on opposite sides of the umbrella; 

 8 lithocjsts ; numerous tentacles : 1 species. 



P. incolorata MeCr. Bell thimble-shaped and colorless; gonads 

 yellowish; tentacles long and brittle and easily broken off; 3 mm. high 

 and half as wide: coasts of North and South Carolina; rare. 



Fig. 201 



Aglantha digitalis 

 (Hargitt). 



Family 3. GEEYONIIDAE. 



Trophosome: wanting. Gonosome: medusa 

 hemispherical; manubrium vei*y long; 6 or 8 en- 

 closed lithocysts; radial canals 4 or 6; gonads plate- 

 like : 2 genera. 



LiRiOPE Lesson. Manubrium extending far 

 beyond the velum and with a square mouth; 4 

 radial canals, between each pair of which are 1 

 to 3 centripetal {i. e., extending from the circular 

 canal upwards) canals, and 4 to 12 tentacles: 20 

 species. 



L. exigua (Quoy and Gaimard) (Fig. 202). 

 Bell hemispherical, 20 mm. wide: Gulf Stream; 

 Mediterranean ; occasionally on the New England 

 coast. 



Order 6. NARCOMEDUSAE. 



Fig. 202 



Liriope exigua 

 (Mayer). 



Trophosome: wanting, so far as known, development being direct, 

 the animals living in the open ocean. Gonosome: medusa with lobed 



