FLABELLINIDAE 309 



to 4. Radula of 80 plates which are horseshoe-shaped and with 6 strong, 

 straight denticles. Not too common. C. aurantiaca A. and H. is the same 

 species. 



Genus Tergipes Cuvier 1805 



Body slender; tentacles simple, the oral pair very short. Branchiae not 

 very numerous, fusiform, inflated, set in a single series on each side of the 

 back; foot narrow, anterior angles rounded. Egg mass kidney-shaped. Rad- 

 ula with a single row of plates, each with a stout central denticle and numer- 

 ous delicate marginal denticles. 



Tergipes despectus Johnston Johnston's Balloon Eolis 



Plate i5d 



Arctic Seas to New York. Europe. 



% inch in length, characters as shown in our figure and in the generic 

 description. Gregarious on hydroids. Shore to 8 fathoms. Common (?). 



Fa7nily GLAUCIDAE 

 Genus Glaucus Forster 1777 



Glaiiciis mamnis Du Pont 1763 Blue Glaucus 



Worldwide, pelagic in warm waters. 



2 inches in length, body elongate, head small. Tentacles and rhinophores 

 very small. 4 clumps of vivid-blue frills on each side of the body. Dorsal 

 side smooth, striped with dark-blue, light-blue and white. Underside pale 

 grayish blue. With strong jaws and a radula of a center row of about 10 

 denticulated teeth. Moderately common at certain seasons. Washed ashore 

 with Janthina, the Purple Sea-snail. G. atlanticiis Forster, G. radiata Gmelin 

 and G, forsteri Lamarck are all this species. 



Family FLABELLINIDAE 

 Genus Eiibranchiis Forbes 1838 



Resembling Tergipes. Radula with central plate with several stout 

 denticles. A triangular lateral tooth is on each side of the central plate, 



Eubranchus exiguiis Alder and Hancock Dwarf Balloon Eolis 



Plate 15c 



Arctic Seas to Boston, Massachusetts. Europe. 



% inch in length, characters as shown in our figure and the generic 

 description. Seasonally uncommon. 



